Highly sensitive detection of prostate cancer specific PCA3 mimic DNA using SERS-based competitive lateral flow assay

Morphology and optical properties of Au-Ag hybrid nanoparticles regulation and its ultra-sensitive SERS immunoassay detection in carbohydrate antigen 19-9

The development of an ultra-sensitive detection method for carbohydrate antigen 19-9 (CA19-9) is very important for the early diagnosis of pancreatic cancer. In this work, we developed a new strategy to achieve a variety of Au-Ag hybrid nanoparticles from janus to core-satellite which is controlled by the volume of AgNO3 and the concentration of benzimidazolecarboxylic acid (MBIA). With the volume of AgNO3 increased, Au-Ag hybrid nanoparticles changed from janus to core-satellite and the characteristic absorption peak showed two opposite trends. The size and number of Ag islands were determined by the concentration of MBIA. Au-Ag core-satellites nanoparticles with a large number of small-sized Ag have the highest SERS intensity. Then we used them as SERS nanotags and Au-Polystyrene nanospheres modified by captured anti-CA19-9 antibody as solid substrates to realize the ultra-sensitive detection of CA19-9 with a low limit of detection of 1.25 × 10-6 IU/mL and a wide linear range of 1.00 × 10-5 -1.00 × 104 IU/mL. This work not only demonstrates that MBIA and AgNO3 were the key factors in the growth of Au-Ag hybrid nanoparticles from 2D to 3D structure but also supplies an ultra-sensitive detection method for CA19-9 which has a potential practicability in the clinical early diagnoses of pancreatic cancer.

SERS-based microdevices for use as in vitro diagnostic biosensors

Advances in surface-enhanced Raman scattering (SERS) detection have helped to overcome the limitations of traditional in vitro diagnostic methods, such as fluorescence and chemiluminescence, owing to its high sensitivity and multiplex detection capability. However, for the implementation of SERS detection technology in disease diagnosis, a SERS-based assay platform capable of analyzing clinical samples is essential. Moreover, infectious diseases like COVID-19 require the development of point-of-care (POC) diagnostic technologies that can rapidly and accurately determine infection status. As an effective assay platform, SERS-based bioassays utilize SERS nanotags labeled with protein or DNA receptors on Au or Ag nanoparticles, serving as highly sensitive optical probes. Additionally, a microdevice is necessary as an interface between the target biomolecules and SERS nanotags. This review aims to introduce various microdevices developed for SERS detection, available for POC diagnostics, including LFA strips, microfluidic chips, and microarray chips. Furthermore, the article presents research findings reported in the last 20 years for the SERS-based bioassay of various diseases, such as cancer, cardiovascular diseases, and infectious diseases. Finally, the prospects of SERS bioassays are discussed concerning the integration of SERS-based microdevices and portable Raman readers into POC systems, along with the utilization of artificial intelligence technology.

Recent advances in SERS-based immunochromatographic assay for pathogenic microorganism diagnosis: A review

Infectious diseases caused by bacteria, viruses, fungi, and other pathogenic microorganisms are among the most harmful public health problems in the world, causing tens of millions of deaths and incalculable economic losses every year. The establishment of rapid, simple, and highly sensitive diagnostic methods for pathogenic microorganisms is important for the prevention and control of infectious diseases, guidance of timely treatment, and the reduction of public safety risks. Lateral flow immunoassay (LFA) based on the colorimetric signal of colloidal gold is the most popular point-of-care testing technology at present, but it is limited by poor sensitivity and low throughput and hardly meets the needs of the highly sensitive screening of pathogenic microorganisms. In recent years, the combination of surface-enhanced Raman scattering (SERS) and LFA technology has developed into a novel analytical platform with high sensitivity and multiple detection capabilities and has shown great advantages in the detection of pathogenic microorganisms and infectious diseases. This review summarizes the working principle, design ideas, and application of the existing SERS-based LFA methods in pathogenic microorganism detection and further introduces the effect of new technologies such as Raman signal encoding, magnetic enrichment, novel membrane nanotags, and integrated Raman reading equipment on the performance of SERS-LFA. Finally, the main challenges and the future direction of development in this field of SERS-LFA are discussed.

Machine learning-assisted global DNA methylation fingerprint analysis for differentiating early-stage lung cancer from benign lung diseases

DNA methylation plays a critical role in the development of human tumors. However, routine characterization of DNA methylation can be time-consuming and labor-intensive. We herein describe a sensitive, simple surface-enhanced Raman spectroscopy (SERS) approach for identifying the DNA methylation pattern in early-stage lung cancer (LC) patients. By comparing SERS spectra of methylated DNA bases or sequences with their counterparts, we identified a reliable spectral marker of cytosine methylation. To move toward clinical applications, we applied our SERS strategy to detect the methylation patterns of genomic DNA (gDNA) extracted from cell line models as well as formalin-fixed paraffin-embedded tissues of early-stage LC and benign lung diseases (BLD) patients. In a clinical cohort of 106 individuals, our results showed distinct methylation patterns in gDNA between early-stage LC (n = 65) and BLD patients (n = 41), suggesting cancer-induced DNA methylation alterations. Combined with partial least square discriminant analysis, early-stage LC and BLD patients were differentiated with an area under the curve (AUC) value of 0.85. We believe that the SERS profiling of DNA methylation alterations, together with machine learning could potentially offer a promising new route toward the early detection of LC.

Design and Synthesis of SERS Materials for In Vivo Molecular Imaging and Biosensing

Surface-enhanced Raman scattering (SERS) is a feasible and ultra-sensitive method for biomedical imaging and disease diagnosis. SERS is widely applied to in vivo imaging due to the development of functional nanoparticles encoded by Raman active molecules (SERS nanoprobes) and improvements in instruments. Herein, the recent developments in SERS active materials and their in vivo imaging and biosensing applications are overviewed. Various SERS substrates that have been successfully used for in vivo imaging are described. Then, the applications of SERS imaging in cancer detection and in vivo intraoperative guidance are summarized. The role of highly sensitive SERS biosensors in guiding the detection and prevention of diseases is discussed in detail. Moreover, its role in the identification and resection of microtumors and as a diagnostic and therapeutic platform is also reviewed. Finally, the progress and challenges associated with SERS active materials, equipment, and clinical translation are described. The present evidence suggests that SERS could be applied in clinical practice in the future.

Ultrasensitive and point-of-care detection of plasma phosphorylated tau in Alzheimer's disease using colorimetric and surface-enhanced Raman scattering dual-readout lateral flow assay

Phosphorylation of tau at Ser (396, 404) (p-tau396,404) is one of the earliest phosphorylation events, and plasma p-tau396,404 level appears to be a potentially promising biomarker of Alzheimer's disease (AD). The low abundance and easy degradation of p-tau in the plasma make the lateral flow assay (LFA) a suitable choice for point-of-care detection of plasma p-tau396,404 levels. Herein, based on our screening of a pair of p-tau396,404-specific antibodies, we developed a colorimetric and surface-enhanced Raman scattering (SERS) dual-readout LFA for the rapid, highly sensitive, and robust detection of plasma p-tau396,404 levels. This LFA realized a detection limit of 60 pg/mL by the naked eye or 3.8 pg/mL by SERS without cross-reacting with other tau species. More importantly, LFA rapidly and accurately differentiated AD patients from healthy controls, suggesting that it has the potential for clinical point-of-care application in AD diagnosis. This dual-readout LFA has the advantages of simple operation, rapid, and ultra-sensitive detection, providing a new way for early AD diagnosis and intervention, especially in primary and community AD screening.

Electronic Supplementary Material

Supplementary material (characterization of AuNPs and 4-MBA@AuNP probe; the optimal 4-MBA load for AuNPs; the optimal K2CO3 volumes for 4-MBA@AuNP-3G5 conjugates; the optimal 3G5 load for 4-MBA@AuNP conjugates; effect of NaCl concentration on 4-MBA@AuNP-3G5 stability; the linear curve of T-line color and SERS intensity versus different p-tau396,404 concentrations; the comparison of colorimetric-based LFA test results and the diagnosis results; Raman intensities and antibody activity of 4-MBA@AuNP-3G5 before and after storage; colorimetric intensity of dual-readout LFA detecting different concentrations of p-tau396,404 protein; sequence of synthesized peptides used in this study; information of the participants in this study; the information of antibodies used in this study) is available in the online version of this article at 10.1007/s12274-022-5354-4.

Integrated SERS-Vertical Flow Biosensor Enabling Multiplexed Quantitative Profiling of Serological Exosomal Proteins in Patients for Accurate Breast Cancer Subtyping

Protein profiles of exosomes (EXOs) in clinical samples of cancer patients have become a promising diagnostic and therapeutic biomarker. However, simultaneous quantitative analysis of multiple exosomal proteins of interest remains challenging. To address the unmet need, we develop a paper-based surface-enhanced Raman spectroscopy (SERS)-vertical flow biosensor, named iREX (integrated Raman spectroscopic EXO) biosensor, for multiplexed quantitative profiling of exosomal proteins in clinical serum samples of patients. Utilizing this iREX biosensor, we are able to quantitatively profile MUC1, HER2 and CEA in EXO samples derived from various breast cancer cell subtypes. The results show discriminative expression profiles of the three exosomal proteins in these cell subtypes, which allows for accurate diagnosis and molecular subtyping of breast cancer. We further validate the clinical utility of the iREX biosensor for simultaneous quantitative analysis of MUC1, HER2 and CEA in patient's blood serums, thereby aiding in noninvasive breast cancer subtyping and longitudinal treatment monitoring. Our iREX biosensor integrating the SERS detection in a vertical flow diagnostic device offers great advantages of high sensitivity, molecular specificity, powerful multiplexing capability, and high diagnostic accuracy. We believe that the iREX biosensor could be a promising clinical tool for comprehensive analysis of exosomal proteins in clinical samples for personalized diagnosis and precise management of breast cancer.

Colorimetric and surface-enhanced Raman scattering dual-mode magnetic immunosensor for ultrasensitive detection of blood phosphorylated tau in Alzheimer's disease

Phosphorylation of tau at Ser 396, 404 (p-tau^396,404) is the earliest phosphorylation event and a promising biomarker for the early diagnosis of Alzheimer's disease (AD). However, the detection of blood p-tau is challenging because of its low abundance, easy degradation, and complex formation with various blood proteins or cells, often leading to the underestimation of p-tau levels in conventional plasma-based assays. Herein, we developed a colorimetric and surface-enhanced Raman scattering (SERS) dual-mode magnetic immunosensor for highly sensitive, specific, and robust detection of p-tau^396,404 in whole blood samples. The detection assay was based on an immunoreaction between p-tau^396,404 proteins, wherein antibody-modified superparamagnetic iron oxide nanoparticles act as recognition elements to capture p-tau^396,404 in blood, and then horseradish peroxidase- and Raman tags label the corresponding paired antibody as a reporter to provide high signal-to-noise ratios for the immunosensor. This dual-mode immunosensor achieved identified as low as 1.5 pg/mL of p-tau^396,404 in the blood in SERS mode and 24 pg/mL in colorimetric mode by the naked eye. More importantly, this immunosensor rapidly and accurately distinguished AD patients from healthy individuals based on blood p-tau^396,404 levels, and also had the potential to distinguish AD patients of different severities. Therefore, the dual-mode immunosensor is promising for rapid clinical diagnosis of AD, especially in large-scale AD screening.

Designing Intelligent Nanomaterials to Achieve Highly Sensitive Diagnoses and Multimodality Therapy of Bladder Cancer

Bladder cancer (BC) is among the most common malignant tumors of the genitourinary system worldwide. In recent years, the rate of BC incidence has increased, and the recurrence rate is high, resulting in poor quality of life for patients. Therefore, how to develop an effective method to achieve synchronous precise diagnoses and BC therapies is a difficult problem to solve clinically. Previous reports usually focus on the role of nanomaterials as drug delivery carriers, while a summary of the functional design and application of nanomaterials is lacking. Summarizing the application of functional nanomaterials in high-sensitivity diagnosis and multimodality therapy of BC is urgently needed. This review summarizes the application of nanotechnology in BC diagnosis, including the application of nanotechnology in the sensoring of BC biomarkers and their role in monitoring BC. In addition, conventional and combination therapies strategy in potential BC therapy are analyzed. Moreover, different kinds of nanomaterials in BC multimodal therapy according to pathological features of BC are also outlined. The goal of this review is to present an overview of the application of nanomaterials in the theranostics of BC to provide guidance for the application of functional nanomaterials to precisely diagnose and treat BC.

Colorimetric and Raman dual-mode lateral flow immunoassay detection of SARS-CoV-2 N protein antibody based on Ag nanoparticles with ultrathin Au shell assembled onto Fe3O4 nanoparticles

Serological antibody tests are useful complements of nuclei acid detection for SARS-CoV-2 diagnosis, which can significantly improve diagnostic accuracy. However, antibody detection in serum or plasma remains challenging to do with high sensitivity. In this study, Ag nanoparticles with ultra-thin Au shells embedded with 4-mercaptobenzoic acid (MBA) (Ag^MBA@Au) were manufactured and then assembled onto Fe₃O₄ surface by electrostatic interaction to construct the Fe₃O₄-Ag^MBA@Au nanoparticles (NPs) with magnetic-Raman-colorimetric properties. Based on the composite nanoparticles, a colorimetric and Raman dual-mode lateral flow immunoassay (LFIA) for ultrasensitive identification of SARS-CoV-2 nucleocapsid (N) protein antibody was constructed. The magnetic nanoparticles (Fe₃O₄ NPs) were acted as the core and coated a layer of Ag^MBA@Au particles on the surface by electrostatic interaction to prepare Fe₃O₄-Ag^MBA@Au NPs, which can amplify the SERS signal due to multiple Ag^MBA@Au particles concentrated on a single magnetic nanoparticle. Moreover, the Fe₃O₄-Ag^MBA@Au NPs facilitated pre-purifying sample using magnetic separation, and complex matrix interference would be greatly decreased in the detection. The Fe₃O₄-Ag^MBA@Au NPs modified with N protein recognized and bound with N protein antibodies, which were trapped on the T-line, forming color band for observing detection. Under optimal conditions, the N protein antibodies could be qualitatively detected in colorimetric mode with the visual limit of 10^-8 mg/mL and quantitatively detected by SERS signals between 10^-6 and 10^-10 mg /mL with 0.08 pg/mL detection limit. The coefficients variations (CV) of intra-assay was 8.0%, whereas of inter-assay was 11.7%, confirming of good reproducibility. Finally, this approach was able to discriminate between positive, negative, and weakly positive samples when detecting 107 clinical serum samples. The process enables highly sensitive quantitative assays that are valuable for evaluating disease processes and guiding treatment. Colorimetric and Raman dual-mode LFIA detection of SARS-CoV-2 N protein antibody based on Fe₃O₄-Ag^MBA@Au nanoparticles.

Biosensors for detection of prostate cancer: a review

Diagnosis of prostate cancer (PC) has posed a challenge worldwide due to the sophisticated and costly diagnostics tools, which include DRE, TRUS, GSU, PET/CT scan, MRI, and biopsy. These diagnostic techniques are very helpful in the detection of PCs; however, all the techniques have their serious limitations. Biosensors are easier to fabricate and do not require any cutting-edge technology as required for other imaging techniques. In this regard, point-of-care (POC) biosensors are important due to their portability, convenience, low cost, and fast procedure. This review explains the various existing diagnostic tools for the detection of PCs and the limitation of these methods. It also focuses on the recent studies on biosensors technologies as an alternative to the conventional diagnostic techniques for the detection of PCs.

Assembly of long silver nanowires into highly aligned structure to achieve uniform "Hot Spots" for Surface-enhanced Raman scattering detection

Silver nanowires (AgNWs) as a promising surface-enhanced Raman spectroscopy (SERS) substrate could be used in the analytical science due to its high sensitivity. However, it is difficult for the randomly-distributed silver nanowires to offer uniform "hot spots" to achieve the SERS signal reproducibility of small molecules detection. Herein, the evaporation-induced aggregation had been used to assemble long silver nanowires into highly aligned structure to achieve uniform "hot spots" for SERS detection. The normal glass slide with well-aligned silver nanowires could act as a high sensitivity and excellent reproducibility SERS substrate to provide a versatile platform for detecting analytes. Rhodamine 6G (R6G) is used to evaluate the sensitivity and reproducibility of these AgNWs SERS substrates. Even the low concentration of the R6G was 10^-10 mol/L, the SERS features of R6G could be still observed clearly, and the uniform distribution of enhancement factor (EF) was higher than 0.8 × 10⁴ accounting for about 75 % in the observed mapping area. Moreover, the relative standard deviation (RSD) of SERS intensity at the band of 610 cm^-1 was used to estimate the signal reproducibility, and the calculated RSD value of aligned AgNWs substrate was about 3.6%, which was much higher than that of the randomly distributed AgNWs (26.8%) because of the highly aligned structure of silver nanowires with abundant and uniform inherent "hot spots". In addition, potential SERS detection of other small molecule, e.g. melamine was also demonstrated in the micromolar range.

Isothermal amplification-mediated lateral flow biosensors for in vitro diagnosis of gastric cancer-related microRNAs

MicroRNAs (miRNAs) are important diagnostic and prognostic biomarkers for various tumors. Currently, many diagnostic systems have been developed to detect miRNAs, but simple techniques for detecting miRNAs are still required. Recently, we reported that the expression of miRNA-135b is upregulated in gastric epithelial cells during gastric inflammation and carcinogenesis. Our aim was to develop an in vitro diagnostic platform to analyze the expression of gastric cancer-related biomarkers in the blood. The diagnostic platform comprised an isothermal amplification-based lateral flow biosensor (IA-LFB) that enables easy diagnosis of gastric cancer through visual observation. In this platform, trace amounts of biomarkers are isothermally amplified through rolling circle amplification (RCA), and the amplified product is grafted to the LFB. The performance of the IA-LFB was confirmed using RNAs extracted from in vitro and in vivo models. The platform could detect target miRNAs within 3 h with excellent sensitivity and selectivity. In particular, the IA-LFB could detect the overexpression of gastric cancer-related markers (miRNA-135b and miRNA-21) in RNAs extracted from the blood of patients with various stages (stages 1-4) of gastric cancer compared to that in healthy volunteers. Therefore, IA-LFB is a simple and sensitive in vitro diagnostic system for detecting gastric cancer-related biomarkers and can contribute to the early diagnosis and prognosis monitoring of gastric cancer. Furthermore, this technology can be applied to systems that can detect multiple biomarkers related to various diseases (such as infectious and genetic diseases).

SERS-based lateral flow immunoassay for sensitive and simultaneous detection of anti-SARS-CoV-2 IgM and IgG antibodies by using gap-enhanced Raman nanotags

The lateral flow immunoassay (LFIA) has played a crucial role in early diagnosis during the current COVID-19 pandemic owing to its simplicity, speed and affordability for coronavirus antibody detection. However, the sensitivity of the commercially available LFIAs needs to be improved to better prevent the spread of the infection. Here, we developed an ultra-sensitive surface-enhanced Raman scattering-based lateral flow immunoassay (SERS-based LFIA) strip for simultaneous detection of anti-SARS-CoV-2 IgM and IgG by using gap-enhanced Raman nanotags (GERTs). The GERTs with a 1 nm gap between the core and shell were used to produce the "hot spots", which provided about 30-fold enhancement as compared to conventional nanotags. The COVID-19 recombinant antigens were conjugated on GERTs surfaces and replaced the traditional colloidal gold for the Raman sensitive detection of human IgM and IgG. The LODs of IgM and IgG were found to be 1 ng/mL and 0.1 ng/mL (about 100 times decrease was observed as compared to commercially available LFIA strips), respectively. Moreover, under the condition of common nano-surface antigen, precise SERS signals proved the unreliability of quantitation because of the interference effect of IgM on IgG.

An efficient SERS platform for the ultrasensitive detection of Staphylococcus aureus and Listeria monocytogenes via wheat germ agglutinin-modified magnetic SERS substrate and streptavidin/aptamer co-functionalized SERS tags

A novel surface-enhanced Raman scattering (SERS)-based analytical technique was proposed to simultaneously detect two highly pathogenic bacteria, namely, Staphylococcus aureus (S. aureus) and Listeria monocytogenes (L. mono) by using a dual-recognition pattern with wheat germ agglutinin (WGA) and nucleic acid aptamers. WGA was modified onto Fe₃O₄@Au magnetic nanoparticles (MNPs) for the efficient capture of S. aureus and L. mono in complex samples (orange juice, extracts of lettuce, and human urine) within 15 min. The streptavidin (SA)/aptamers co-functionalized SERS tags were fabricated by covalent attaching two different Raman reporters and SA molecules onto 45 nm Au NPs and then conjugated with two biotin-aptamers that specifically bind to their target bacteria with high affinity and stability. The combined use of high-sensitive SERS tags, WGA-mediated magnetic enrichment, and SA-mediated aptamer conjugation remarkably improved the assay sensitivity. Under optimized conditions, the developed SERS biosensor can simultaneously detect the two target bacteria with high detection sensitivity (<6 cells/mL), favorable linear relation (10-10⁷ cells/mL), and high accuracy (recovery rate <7.03%). Therefore, the proposed SERS platform is rapid, sensitive, easy to use, and thus show potential as a tool for the timely identification of pathogenic bacteria in real samples.

An origami paper-based peptide nucleic acid device coupled with label-free DNAzyme probe hybridization chain reaction for prostate cancer molecular screening test

Prostate cancer associated 3 (PCA3) assay has been used to improve prostate cancer diagnosis and reduce unnecessary biopsies. In this work, we successfully developed a new PCA3 assay on an origami paper-based peptide nucleic acid device (oPAD). The PCA3 oPAD comprises an acrylic cassette and shutter slides to facilitate the molecular reaction and liquid control occurring on the paper surface. To quantify PCA3, a pyrrolidinyl peptide nucleic acid (acpcPNA) was immobilized onto the aldehyde-modified oPAD surface as a selective capture probe. A G-quadruplex (GQD) DNAzyme reporter probe was designed so that the PCA3 gene target binding triggered the hybridization chain reaction of the reporter probe, resulting in the accumulation of the GQD on the oPAD. The peroxidase activity of the GQD-hemin generated a deep green color of the oxidized ABTS substrate. Image analyses were performed in Adobe Photoshop CS6. The proposed oPAD was successfully applied in PCA3 detection ranges of 1-5 μM (r² = 0.982) with a limit of detection of 0.5 μM. Our proposed oPAD was demonstrated to measure PCA3 samples in both urine matrix and human cancer cell lines. The results reveal the great potential of our origami paper-based platform to be an alternative approach for facile, rapid, and low-cost detection of PCA3 in real samples.

Raman Imaging and Fluorescence Lifetime Imaging Microscopy for Diagnosis of Cancer State and Metabolic Monitoring

Hurdles for effective tumor therapy are delayed detection and limited effectiveness of systemic drug therapies by patient-specific multidrug resistance. Non-invasive bioimaging tools such as fluorescence lifetime imaging microscopy (FLIM) and Raman-microspectroscopy have evolved over the last decade, providing the potential to be translated into clinics for early-stage disease detection, in vitro drug screening, and drug efficacy studies in personalized medicine. Accessing tissue- and cell-specific spectral signatures, Raman microspectroscopy has emerged as a diagnostic tool to identify precancerous lesions, cancer stages, or cell malignancy. In vivo Raman measurements have been enabled by recent technological advances in Raman endoscopy and signal-enhancing setups such as coherent anti-stokes Raman spectroscopy or surface-enhanced Raman spectroscopy. FLIM enables in situ investigations of metabolic processes such as glycolysis, oxidative stress, or mitochondrial activity by using the autofluorescence of co-enzymes NADH and FAD, which are associated with intrinsic proteins as a direct measure of tumor metabolism, cell death stages and drug efficacy. The combination of non-invasive and molecular-sensitive in situ techniques and advanced 3D tumor models such as patient-derived organoids or microtumors allows the recapitulation of tumor physiology and metabolism in vitro and facilitates the screening for patient-individualized drug treatment options.

Nanostructure-based surface-enhanced Raman scattering for diagnosis of cancer

Cancer is a malignant disease that seriously affects human health and life. Early diagnosis and timely treatment can significantly improve the survival rate of cancer patients. Surface-enhanced Raman scattering (SERS) is an optical technology that can detect and image samples at the single-molecule level. It has the advantages of rapidity, high specificity, high sensitivity and no damage to the sample. The performance of SERS is highly dependent on the properties, size and morphology of the SERS substrate. Preparation of SERS substrates with good reproducibility and chemical stability is a key factor in realizing the wide application of SERS technology in cancer diagnosis. In this review we provide a detailed presentation of the latest research on SERS in cancer diagnosis and the detection of cancer biomarkers, mainly focusing on nanotechnological approaches in cancer diagnosis by using SERS. We also consider the future development of nanostructure-based SERS in cancer diagnosis.

Novel Prostate Cancer Biomarkers: Aetiology, Clinical Performance and Sensing Applications

The review initially provides a short introduction to prostate cancer (PCa) incidence, mortality, and diagnostics. Next, the need for novel biomarkers for PCa diagnostics is briefly discussed. The core of the review provides details about PCa aetiology, alternative biomarkers available for PCa diagnostics besides prostate specific antigen and their biosensing. In particular, low molecular mass biomolecules (ions and metabolites) and high molecular mass biomolecules (proteins, RNA, DNA, glycoproteins, enzymes) are discussed, along with clinical performance parameters.

Modification of a nitrocellulose membrane with nanofibers for sensitivity enhancement in lateral flow test strips

Lateral-flow analysis (LFA) is a convenient, low-cost, and rapid detection method, which has been widely used for screening of diseases. However, sensitivity enhancement in LFA is still a focus in this field and remains challenging. Herein, we propose an electrospinning coating method to modify the conventional nitrocellulose (NC) membrane and optimize the liquid flow rate for enhancing the sensitivity of the NC based LFA strips in the detection of human chorionic gonadotropin (HCG) and luteinizing hormone (LH). It can be seen that coating the NC membrane with nitrocellulose fibers could obtain a NC based strip with HCG and LH detection limits of 0.22 and 0.36 mIU mL-1 respectively, and a quantitative linear range of 0.5-500 mIU mL-1. The results show that electrospinning is effective in modifying conventional NC membranes for LFA applications.

Tissue- and Liquid-Based Biomarkers in Prostate Cancer Precision Medicine

Worldwide, prostate cancer (PC) is the second-most-frequently diagnosed male cancer and the fifth-most-common cause of all cancer-related deaths. Suspicion of PC in a patient is largely based upon clinical signs and the use of prostate-specific antigen (PSA) levels. Although PSA levels have been criticised for a lack of specificity, leading to PC over-diagnosis, it is still the most commonly used biomarker in PC management. Unfortunately, PC is extremely heterogeneous, and it can be difficult to stratify patients whose tumours are unlikely to progress from those that are aggressive and require treatment intensification. Although PC-specific biomarker research has previously focused on disease diagnosis, there is an unmet clinical need for novel prognostic, predictive and treatment response biomarkers that can be used to provide a precision medicine approach to PC management. In particular, the identification of biomarkers at the time of screening/diagnosis that can provide an indication of disease aggressiveness is perhaps the greatest current unmet clinical need in PC management. Largely through advances in genomic and proteomic techniques, exciting pre-clinical and clinical research is continuing to identify potential tissue, blood and urine-based PC-specific biomarkers that may in the future supplement or replace current standard practices. In this review, we describe how PC-specific biomarker research is progressing, including the evolution of PSA-based tests and those novel assays that have gained clinical approval. We also describe alternative diagnostic biomarkers to PSA, in addition to biomarkers that can predict PC aggressiveness and biomarkers that can predict response to certain therapies. We believe that novel biomarker research has the potential to make significant improvements to the clinical management of this disease in the near future.

An update on our ability to monitor castration-resistant prostate cancer dynamics with cell-free DNA

Introduction: Prostate cancer is one of the most frequent tumors worldwide. Due to the lack of reliable markers, patients are usually diagnosed at a late stage when it becomes castration-resistant prostate cancer (CRPC) with a worse outcome. Thus, it is essential to ameliorate the clinical management of these patients. Nowadays, the use of liquid biopsy represents a minimally invasive way to provide a complete molecular landscape of prostate cancer. Thus, this review aims to outline the clinical value of cell-free DNA in real-time monitoring of metastatic CRPC (mCRPC).Areas covered: This comprehensive review explores in detail the characteristics as well as clinical applications of plasma DNA analysis in mCRPC.Expert opinion: The assessment of circulating tumor DNA fraction is a valid and robust biomarker in mCRPC able to predict clinical outcome and monitor disease evolution during treatment. Recently, several methods (i.e. next generation sequencing and digital droplet PCR) are used to investigate genomics in cell-free DNA and novel nanotechnology-based approaches are currently under evaluation in order to improve clinical management of mCRPC patients.

SERS-based test strips: Principles, designs and applications

Test strips represent a class of point-of-care testing (POCT) tools for analysis of a variety of biomarkers towards diagnostics. Conventional test strips offer benefits of simple operation, visualization, and short detection time, along with the drawbacks of relatively low sensitivity and unavailability of quantitative analysis. Recently, the combination of surface-enhanced Raman scattering (SERS) and test strips have evolved to provide a powerful platform capable of ultrasensitive and multiplex detection of extensive analytes of interest. In this review, we focus on the working principles, design strategies and POCT applications of SERS-based test strips. Initially, both lateral and vertical flow test strips are briefly introduced, followed by presentation of various strategies for reforming SERS-based test strips with better detection performance. Applications of SERS-based test strips in diagnosis of disease biomarkers, nucleic acids and toxins are reviewed, with an emphasis on SERS tag design, sensitivity and analytical applicability. Finally, conclusions are made and perspectives on futuristic research directions are given.

Pre-clinically evaluated visual lateral flow platform using influenza A and B nucleoprotein as a model and its potential applications

A visual colorimetric rapid screening system based on a lateral flow device for simultaneous detection and differentiation between influenza A and B nucleoprotein as a model was developed. Monoclonal antibodies, specific for either influenza A or B nucleoproteins, were evaluated for their reactivities and were used as targeting ligands. With the best antibody pairs selected, the system exhibited good specificity to both viruses without cross reactivity to other closely related respiratory viruses. Further semi-quantitative analysis using a strip reader revealed that the system is capable of detecting influenza A and B protein content as low as 0.04 and 1 ng per test, respectively, using a sample volume as low as 100 μL, within 10 minutes (R² = 0.9652 and 0.9718). With a performance comparison to the commercial tests, the system demonstrated a four-to-eight-fold higher sensitivity. Pre-clinical evaluation with 101 nasopharyngeal swabs reveals correlated results with a standard molecular approach, with 89% and 83% sensitivity towards influenza A and B viruses, and 100% specificity for both viruses.

Visual colorimetric rapid screening system based on lateral flow device for influenza A and B virus detection as a model and its pre-clinical evaluation.

Dual-signal lateral flow assay using vancomycin-modified nanotags for rapid and sensitive detection of Staphylococcus aureus

This paper reports a colorimetric-fluorescent dual-signal lateral flow assay (LFA) based on vancomycin (Van)-modified SiO2-Au-QD tags for sensitive and quantitative detection of Staphylococcus aureus (S. aureus). The combination of high-performance Van-tags and detection antibodies integrated into the LFA system produced assays with high sensitivity and specificity. The visualization limit of the colorimetric signal and the detection limit of the fluorescence signal of the proposed method for S. aureus can reach 104 and 100 cells mL-1, respectively.

Au-Ag assembled on silica nanoprobes for visual semiquantitative detection of prostate-specific antigen

Background

Blood prostate-specific antigen (PSA) levels are widely used as diagnostic biomarkers for prostate cancer. Lateral-flow immunoassay (LFIA)-based PSA detection can overcome the limitations associated with other methods. LFIAbased PSA detection in clinical samples enables prognosis and early diagnosis owing to the use of high-performance signal reporters.

Results

Here, a semiquantitative LFIA platform for PSA detection in blood was developed using Au–Ag nanoparticles (NPs) assembled on silica NPs (SiO2@Au–Ag NPs) that served as signal reporters. Synthesized SiO2@Au–Ag NPs exhibited a high absorbance at a wide wavelength range (400–800 nm), with a high scattering on nitrocellulose membrane test strips. In LFIA, the color intensity of the test line on the test strip differed depending on the PSA concentration (0.30–10.00 ng/mL), and bands for the test line on the test strip could be used as a standard. When clinical samples were assessed using this LFIA, a visual test line with particular color intensity observed on the test strip enabled the early diagnosis and prognosis of patients with prostate cancer based on PSA detection. In addition, the relative standard deviation of reproducibility was 1.41%, indicating high reproducibility, and the signal reporter showed good stability for 10 days.

Conclusion

These characteristics of the signal reporter demonstrated the reliability of the LFIA platform for PSA detection, suggesting potential applications in clinical sample analysis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-00817-4.

Simultaneous and ultrasensitive detection of three pesticides using a surface-enhanced Raman scattering-based lateral flow assay test strip

Chlorothalonil (CHL), imidacloprid (IMI) and oxyfluorfen (OXY) are commonly used in combination to increase crop yield. However, these three pesticides are toxic to aquatic organisms and do not easily degrade. In this study, a surface-enhanced Raman scattering-based lateral flow assay (SERS-LFA) test strip was prepared by combining antibodies with SERS nanotags, and then competitive immune binding was used to detect the three pesticides simultaneously. Moreover, the two-way binding effect of ssDNA-streptavidin bound to Ag^4-NTP@AuNPs and Ag^4-NTP@AuNPs with antibodies was used to further amplify the detection signal. Under the optimal conditions, the SERS-LFA test strips exhibited high sensitivity, a low detection limit, short detection time, high specificity and low cost. Furthermore, the detection range was within the values prescribed by international detection standards. By measuring the intensity of the SERS signal on the test line of the paper strip, accurate quantitative analysis was achieved. The practical application of the proposed system was demonstrated by simultaneous detection of CHL, IMI and OXY in environmental and food samples with satisfactory results.

Recent advances in sensitive surface-enhanced Raman scattering-based lateral flow assay platforms for point-of-care diagnostics of infectious diseases

This review reports the recent advances in surface-enhanced Raman scattering (SERS)-based lateral flow assay (LFA) platforms for the diagnosis of infectious diseases. As observed through the recent infection outbreaks of COVID-19 worldwide, a timely diagnosis of the disease is critical for preventing the spread of a disease and to ensure epidemic preparedness. In this regard, an innovative point-of-care diagnostic method is essential. Recently, SERS-based assay platforms have received increasing attention in medical communities owing to their high sensitivity and multiplex detection capability. In contrast, LFAs provide a user-friendly and easily accessible sensing platform. Thus, the combination of LFAs with a SERS detection system provides a new diagnostic modality for accurate and rapid diagnoses of infectious diseases. In this context, we briefly discuss the recent application of LFA platforms for the POC diagnosis of SARS-CoV-2. Thereafter, we focus on the recent advances in SERS-based LFA platforms for the early diagnosis of infectious diseases and their applicability for the rapid diagnosis of SARS-CoV-2. Finally, the key issues that need to be addressed to accelerate the clinical translation of SERS-based LFA platforms from the research laboratory to the bedside are discussed.

Simplified formats of modern biosensors: 60 years of using immunochromatographic test systems in laboratory diagnostics

Immunochromatographic test systems known to foreign laboratory diagnostic experts as lateral flow immunoassay (LFIA) are simplified tape formats of modern biosensors. For 60 years, they have been widely used for the rapid detection of target molecules (ligands) in biosubstrates and the diagnosis of many diseases and conditions. The growing popularity of these test systems for providing medical care or diagnostics in developing countries, medical facilities, in emergency situations, as well as for individual home use by patients while monitoring their health are the main factors contributing to the continuous development and improvement of these methods, the emergence of a new generation of formats. The attractiveness and popularity of these fast, easy-to-use, inexpensive and portable diagnostic tools is associated primarily with their high analytical sensitivity and specificity, as well as the ease of interpretation of the results. These qualities have passed the test of time, and today LFIA test systems are fully consistent with the modern world concept of «point-of-care testing», finding wide application not only in medicine, but also in ecology, veterinary medicine, and agriculture. This review will highlight the modern principles of designing the most widely used formats of immunochromatographic test systems for clinical laboratory diagnostics, summarize the main advantages and disadvantages of the method, as well as current achievements and prospects of LFIA technology. Modern innovations aimed at improving the analytical characteristics of LFIA technology are interesting, promising and can bring additional benefits to immunochromatographic platforms that have gained popularity and attractiveness for six decades.

DNA-assisted synthesis of Ortho-NanoDimer with sub-nanoscale controllable gap for SERS application

Nanostructure with precisely controllable narrow gap width remains a great challenge, especially at the sub-nanoscale level. Here, a versatile strategy named as DNA-assisted synthesis of ortho-nanodimer (DaSON) is proposed to fabricate Ag (Au) nanodimers with a uniform gap width from nanometers to angstroms. In such a strategy, two nanoparticles are constrained by the equilibrium state of the DNA hybridization and electrostatic repulsion to form zipper-like ortho-nanostructures with an extremely uniform gap whose width can be finely adjusted at nanoscale or sub-nanoscale by changing the DNA sequence and the surface charge of nanoparticles. The inherent strong electromagnetic coupling in the uniform sub-nanometer gap can generates an unparalleled SERS enhancement together with an extraordinary reproducibility. Compared with conventional DNA-based nano-gap fabrication strategy, the DaSON strategy enhances the SERS intensity for more than two orders of magnitude with a detection limit of 100 aM for DNA, and significantly improves the reproducibility in both labeled and label-free SERS sensing applications. Moreover, the DaSON strategy holds wide applicability for arbitrary kinds of DNA-modifiable nanoparticles. Therefore, we believe that the DaSON strategy provides an innovative method for the synthesis of nanostructures with controllable nanogaps and has a promising future in multiple fields including nanotechnology, catalysis and photonics.

Quantitative and ultrasensitive detection of brombuterol by a surface-enhanced Raman scattering (SERS)-based lateral flow immunochromatographic assay (FLIA) using AgMBA@Au-Ab as an immunoprobe

Brombuterol is a new emerging β-adrenergic agonist that has been used as an additive in animal feed to enhance the lean meat-to-fat ratio. Due to its potential harm to consumers, it is urgent to develop sensitive, simple and rapid analytical methods to monitor brombuterol residue. In this study, a competitive lateral flow immunochromatographic assay (FLIA) based on surface-enhanced Raman scattering (SERS) was developed for ultrasensitive quantitative determination of brombuterol in swine liver, pork and feed samples. Ag@Au core-shell bimetallic nanoparticles with the highest SERS enhancement were synthesized, characterized and used as the substrate for preparation of the immunoprobe AgMBA@Au-Ab, in which the Raman reporter mercaptobenzoic acid (MBA) was embedded between the core-shell layers and monoclonal antibodies against brombuterol were immobilized on the surfaces of nanoparticles. The presence of brombuterol was identified through a color change on testing lines. In addition, quantitative detection of brombuterol was achieved by measuring the characteristic Raman peak intensity of MBA in the immunoprobes captured by the coating antigen. The IC50 and limit of detection (LOD) of the SERS-based FLIA for brombuterol were 45 pg mL-1 and 0.11 pg mL-1, respectively. The recoveries of brombuterol from spiked samples were in the range of 87.27-100.16% with relative standard deviations of 1.29%-6.99% (n = 3). The proposed SERS-based LFIA was proven to be a feasible method for ultrasensitive and rapid detection of brombuterol and might be a platform for sensitive and rapid detection of a broad range of analytes in clinical, environmental and food analyses.

SERS-based immunoassay using core–shell nanotags and magnetic separation for rapid and sensitive detection of cTnI

Au-4MBA@Ag with a strong Raman signal was successfully synthesized, and combination with magnetic separation technology achieved sensitive detection of cTnI.

A portable SERS reader coupled with catalytic hairpin assembly for sensitive microRNA-21 lateral flow sensing

A sensitive lateral flow sensing platform has been constructed using a portable SERS meter coupled with catalytic hairpin assembly.

Upconverting nanoparticle clustering based rapid quantitative detection of tetrahydrocannabinol (THC) on lateral-flow immunoassay

Cannabis, also known as marijuana, is the most abused psychoactive drug worldwide.

Rapid point-of-care testing methods/devices for meat species identification: A review

The authentication of animal species is an important issue due to an increasing trend of adulteration and mislabeling of animal species in processed meat products. Polymerase chain reaction is the most sensitive and specific technique for nucleic acid-based animal species detection. However, it is a time-consuming technique that requires costly thermocyclers and sophisticated labs. In recent times, there is a need of on-site detection by point-of-care (POC) testing methods and devices under low-resource settings. These POC devices must be affordable, sensitive, specific, user-friendly, rapid and robust, equipment free, and delivered to the end users. POC devices should also confirm the concept of micro total analysis system. This review discusses POC testing methods and devices that have been developed for meat species identification. Recent developments in lateral flow assay-based devices for the identification of animal species in meat products are also reviewed. Advancements in increasing the efficiency of lateral flow detection are also discussed.

Surface-Enhanced Raman Scattering-Based Lateral-Flow Immunoassay

Lateral flow immunoassays (LFIAs) have been developed and used in a wide range of applications, in point-of-care disease diagnoses, environmental safety, and food control. However, in its classical version, it has low sensitivity and can only perform semiquantitative detection, based on colorimetric signals. Over the past decade, surface-enhanced Raman scattering (SERS) tags have been developed in order to decrease the detection limit and enable the quantitative analysis of analytes. Of note, these tags needed new readout systems and signal processing algorithms, while the LFIA design remained unchanged. This review highlights SERS strategies of signal enhancement for LFIAs. The types of labels used, the possible gain in sensitivity from their use, methods of reading and processing the signal, and the prospects for use are discussed.

Six decades of lateral flow immunoassay: from determining metabolic markers to diagnosing COVID-19

Technologies based on lateral flow immunoassay (LFIA), known in some countries of the world as immunochromatographic tests, have been successfully used for the last six decades in diagnostics of many diseases and conditions as they allow rapid detection of molecular ligands in biosubstrates. The popularity of these diagnostic platforms is constantly increasing in healthcare facilities, particularly those facing limited budgets and time, as well as in household use for individual health monitoring. The advantages of these low-cost devices over modern laboratory-based analyzers come from their availability, opportunity of rapid detection, and ease of use. The attractiveness of these portable diagnostic tools is associated primarily with their high analytical sensitivity and specificity, as well as with the easy visual readout of results. These qualities explain the growing popularity of LFIA in developing countries, when applied at small hospitals, in emergency situations where screening and monitoring health condition is crucially important, and as well as for self-testing of patients. These tools have passed the test of time, and now LFIA test systems are fully consistent with the world's modern concept of ‘point-of-care testing’, finding a wide range of applications not only in human medicine, but also in ecology, veterinary medicine, and agriculture. The extensive opportunities provided by LFIA contribute to the continuous development and improvement of this technology and to the creation of new-generation formats. This review will highlight the modern principles of design of the most widely used formats of test-systems for clinical laboratory diagnostics, summarize the main advantages and disadvantages of the method, as well as the current achievements and prospects of the LFIA technology. The latest innovations are aimed at improving the analytical performance of LFIA platforms for the diagnosis of bacterial and viral infections, including COVID-19.

Simultaneous and accurate visual identification of chicken, duck and pork components with the molecular amplification integrated lateral flow strip

We propose a visual strategy for simultaneous detection of multiple adulterated components in beef by integration of multiple polymerase chain reaction (mPCR) with the lateral flow strip (LFS). The primer sets for adulterated components are uniquely designed with different nucleic acid tags (NAT), enabling the amplicons with specific wobbled sequences at two opposite ends. The wobbled sequences will precisely hybridize with the pre-immobilized capture probes on T lines (T1, T2 and T3) and C line, contributing to the coloration of LFS. Taking advantages of extraordinary amplification efficiency of PCR and simplicity of LFS, common adulterated components including chicken, duck and pork can be easily detected with LOD as low as 0.01% (wt%), which is comparable to that of quantitative real-time polymerase chain reaction (qPCR) but with more simplified operations and reduced costs. The method can be extended to identification of other components by replacing the functional primer set. This method can be a useful candidate for meat quality control at the resource-limited setups.

Electrochemical biosensor for detection of MON89788 gene fragments with spiny trisoctahedron gold nanocrystal and target DNA recycling amplification

The shape-controlled synthesis of gold nanocrystals via shape induction of hexadecyltrimethylammonium chloride, potassium bromide, and potassium iodide and enantioselective direction of L-cysteine is reported. The resulting gold nanocrystals (STO-Au) offer spiny trisoctahedron nanostructures with good monodispersity and enhanced exposed high-index facets and high catalytic activity. Construction of the electrochemical sensing platform for MON89788 gene involves the modification of STO-Au, thionine (Thi), and labeled bipedal DNA probe 1 or 2 (P1 or P2) for target DNA-induced recycling amplification. In the detection, two surface DNA probes were immobilized on gold electrode via the Au-S bond. Then, hairpin DNA 1 (H1), Thi-STO-Au-P1, and Thi-STO-Au-P2 self-assemble into two-dimensional DNA nanopores (DNPs) on the electrode surface. Target DNA hybridizes with hairpin DNA 2 (H2) to open hairpin structure of H2. The opened H2 binds with H1 in the DNPs to release Thi-STO-Au-P1, Thi-STO-Au-P2, and target DNA by toehold-mediated strand-displacement. The utilization of target DNA-induced recycling allows one target DNA to release 2N STO-Au-labeled DNA strands, promoting significant signal amplification. The detection signal is further enhanced by the catalyzed redox reaction of Thi with STO-Au. The differential pulse voltammetric signal, best measured at - 0.18 V vs. Ag/AgCl, decreases linearly with increasing concentration of MON89788 in the range 0.02-8 × 104 fM, and the detection limit is 0.0048 fM (S/N = 3). The proposed method was successfully applied for electrochemical detection of MON89788 gene fragments in the PCR products from genetically modified soybean. Graphical Abstract We develop l-cysteine controlled synthesis of spiny trisoctahedron gold nanocrystals with good monodispersity and highly exposed high-index facets. The architecture achieves to ultrahigh catalytic activity. The electrochemical biosensor based on gold nanocrystals and target DNA recycling amplification provides advantage of sensitivity, repeatability, and regeneration-free.

Electrochemical and optical detection and machine learning applied to images of genosensors for diagnosis of prostate cancer with the biomarker PCA3

The development of simple detection methods aimed at widespread screening and testing is crucial for many infections and diseases, including prostate cancer where early diagnosis increases the chances of cure considerably. In this paper, we report on genosensors with different detection principles for a prostate cancer specific DNA sequence (PCA3). The genosensors were made with carbon printed electrodes or quartz coated with layer-by-layer (LbL) films containing gold nanoparticles and chondroitin sulfate and a layer of a complementary DNA sequence (PCA3 probe). The highest sensitivity was reached with electrochemical impedance spectroscopy with the detection limit of 83 pM in solutions of PCA3, while the limits of detection were 2000 pM and 900 pM for cyclic voltammetry and UV–vis spectroscopy, respectively. That detection could be performed with an optical method is encouraging, as one may envisage extending it to colorimetric tests. Since the morphology of sensing units is known to be affected in detection experiments, we applied machine learning algorithms to classify scanning electron microscopy images of the genosensors and managed to distinguish those exposed to PCA3-containing solutions from control measurements with an accuracy of 99.9%. The performance in distinguishing each individual PCA3 concentration in a multiclass task was lower, with an accuracy of 88.3%, which means that further developments in image analysis are required for this innovative approach.

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Low-cost biosensors fabricated with gold nanoparticles and chondroitin sulfate used for detecting PCA3 biomarker.

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PCA3 detection from machine learning with accuracy of 99.9%.

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The highest sensitivity was reached with electrochemical impedance spectroscopy with the detection limit of 83 pM.

Quaternary-Ammonium-Modulated Surface-Enhanced Raman Spectroscopy Effect: Discovery, Mechanism, and Application for Highly Sensitive In Vitro Sensing of Acetylcholine

Quaternary ammonium (QA) plays multiple roles in biological functions, whose dysregulation may result in multiple diseases. However, how to efficiently detect QA-based materials such as acetylcholine (ACh) still remains a great challenge, especially in complex biological environments. Here, a new effect [called quaternary-ammonium-modulated surface-enhanced Raman spectroscopy (QAM-SERS) effect] is discovered, showing that the existence of QA will modulate the intensity of SERS signals in a concentration-dependent manner. When the QAM-SERS effect is used, a new method is easily developed for in vitro detection of ACh with an extremely high sensitivity and an ultrawide dynamic range. Particularly, the linear dynamic range can be freely tuned to adapt for various physiological samples. As a proof-of-concept experiment, the time-dependent secretion of ACh from PC12 cells was successfully monitored using the QAM-SERS method, which were under either the stimulation of potassium ions or the incubation of drugs. The discovery of the QAM-SERS effect provides an easy and universal strategy for detecting ACh as well as other QA-contained molecules, which can also inspire new insights into the roles that QA could play in biology and chemistry.

A novel immunosensor for the monitoring of PSA using binding of biotinylated antibody to the prostate specific antigen based on nano-ink modified flexible paper substrate: efficient method for diagnosis of cancer using biosensing technology

Prostate cancer is the most significant reason for deaths in men, outside of lung cancer. The clinical examination of cancer proteins or biomarkers is extremely significant in early examination and monitoring of recurrence of disease after treatment. Biomarkers have expanded great clinical significance owing to their extensive spectra in the identification, elimination, early diagnosis and cure of cancer. In this work, novel, ultrasensitive sandwich-type portable bio device based on citrate-capped silver nanoparticles (Citrate-AgNPs) modified graphene quantum dots (GQDs) nano ink for detection of Prostate specific antigen (PSA) was fabricated. Functionalized cysteamine with gold nanoparticles (Cys-AuNPs) was also utilized to amplify the signal. It provides a good and high external area for the immobilization biotinylated antibody of PSA in the large amount. For the first time, citrate-AgNPs-GQDs nano ink was directly written on the cellulose paper surface (ivory sheet and photographic paper) and modified by Cys-AuNPs. So, final structure of the immunodevices was completed after including of Ab1 and PSA (antigen). The immunosensors were used for the recognition of PSA by using DPVs (differential pulse voltammetry) technique. The obtained low limit of quantification (LLOQ) of the first immunodevice (ivory sheet/Citrate AgNPs-GQDs nano-ink/CysA-Au NPs/Ab1/BSA/PSA/Ab2) was 0.07 μg/L and the linear range for the calibration plot was from 0.07 to 60 μg/L. Also, the achieved LLOQ of the second immunodevice (photographic paper/Citrate AgNPs-GQDs nano-ink/Cys-Au NPs/Ab1/BSA/PSA/Ab2) was 0.05 μg/L with the linear range of 10 to 0.05 μg/L. It is noteworthy that, proposed immunoassay was effectively utilized to the monitoring of PSA glycoprotein in unprocessed human plasma sample. Obtained results show that the constructed immunosensor is able to apply as portable bio device for the clinical analysis of PSA in human plasma samples.