Molecularly imprinted based surface plasmon resonance nanosensors for microalbumin detection

A novel glass chip based lateral flow immunoassay of albumin

Lateral flow immunoassays typically rely on optical tests conducted on paper strips. However, the 3D matrix of paper embedded with optical nanoparticles often limits detection sensitivity and the ability of detection instruments to capture signals. This study introduces a novel approach using a glass chip-based lateral flow immunoassay, with albumin as a typical biomarker for detection, enabling the presence of the signal on a flat surface. Compared with traditional paper-based immunoassay, glass-based lateral flow immunoassay has achieved a uniform distribution pattern for albumin detection, lowered the limit of detection from 100 ng/mL to 1 ng/mL, and reduced detection time through an improved liquid mobility system. The glass-based method also shortens the detection time by 28.5% to 147.8 s compared to the traditional method. This research presents a new methodology for lateral flow immunoassays that can be applied to a wide range of biomarkers, with potential benefits for various medical and environmental applications.

A Review Study on Molecularly Imprinting Surface Plasmon Resonance Sensors for Food Analysis

Surface plasmon resonance (SPR) sensors have emerged as a powerful tool in biosensing applications due to their ability to provide sensitive and real-time detection of chemical and biological analytes. This review focuses on the development and application of molecularly imprinted polymer (MIP)-based SPR sensors for food analysis. By combining the high selectivity of molecular imprinting techniques with the sensitivity of SPR, these sensors offer significant advantages in detecting food contaminants and other target molecules. The article covers the basic principles of SPR, the role of MIPs in sensor specificity, recent advancements in this sensor development, and food applications. Furthermore, the potential for these sensors to contribute to food safety and quality control was explored, showcasing their adaptability to complex food matrices. The review concluded the future directions and challenges of SPR-MIP sensors in food analysis, emphasizing their promise in achieving high-throughput, cost-effective, and portable sensing solutions.

Molecularly imprinted polymers for sensing/depleting human serum albumin (HSA): A critical review of recent advances and current challenges

Human serum albumin (HSA) is an essential biomacromolecule in the blood circulatory system because it carries numerous molecules, including fatty acids (FAs), bilirubin, metal ions, hormones, and different pharmaceuticals, and plays a significant role in regulating blood osmotic pressure. Fluctuations in HSA levels in human biofluids, particularly urine and serum, are associated with several disorders, such as elevated blood pressure, diabetes mellitus (DM), liver dysfunction, and a wide range of renal diseases. Thus, the ability to quickly and accurately measure HSA levels is important for the rapid identification of these disorders in human populations. Molecularly imprinted polymers (MIPs), well known as artificial antibodies (Abs), have been extensively used for the quantitative detection of small molecules and macromolecules, especially HSA, in recent decades. This review highlights major challenges and recent developments in the application of MIPs to detect HSA in artificial and real samples. The fabrication and application of various MIPs for the depletion of HSA are also discussed, as well as different MIP preparation approaches and strategies for overcoming obstacles that hinder the development of MIPs with high efficiency and recognition capability for HSA determination/depletion.

Cibacron Blue F3GA ligand dye-based magnetic silica particles for the albumin purification

Dye-ligand affinity chromatography is among the increasingly popular affinity chromatography based on molecular recognition for the purification of albumin. This study focuses on the binding of Cibacron Blue F3GA ligand dye with magnetic silica particles and purification by separation. Mono-disperse silica particles with bimodal pore size distribution were employed as a high-performance adsorbent for human serum albumin (HSA) protein purification under equilibrium conditions. The synthesized ligand-dye affinity based magnetic silica particles were characterized by electron spin resonance, Fourier-transform infrared spectroscopy, scanning electron microscopy, vibrating sample magnetometer, elemental analysis, and dispersive X-ray analysis. The HSA purification performance of the proposed material in the presence of a magnetic field was relatively investigated using magnetic-based particles with similar morphologies. The maximum adsorption capacity for HSA in an artificial plasma medium was defined as 48.6 mg/g magnetic silica particle. By using the designed magnetic silica particles, 1.0 M NaCl solution was successfully utilized for obtaining quantitative desorption with HSA. However, continued HSA purification performances of magnetic-based particles were significantly lower concerning the ligand-dye magnetic silica particles. The purity of the removed albumin was about 97%. The magnetic silica particles could be utilized many times without decreasing their protein adsorption capacities remarkably.

Electrochemical Detection of Cortisol by Silver Nanoparticle-Modified Molecularly Imprinted Polymer-Coated Pencil Graphite Electrodes

The sensitive cortisol detection by an electrochemical sensor based on silver nanoparticle-doped molecularly imprinted polymer was successfully improved. This study describes the method development for cortisol detection in both aqueous solution and biological samples using molecularly imprinted poly(hydroxyethyl methacrylate-N-methacryloyl-(l)-histidine methyl ester)-coated pencil graphite electrodes modified with silver nanoparticles (AgNPs) by differential pulse voltammetry (DPV). The cortisol-imprinted pencil graphite electrode (PGE) has a large surface area because of doped AgNPs with enhanced electroactivity. The prepared molecularly imprinted polymer was characterized by scanning electron microscopy. The DPV response of the synthesized electrode with outstanding electrical conductivity was clarified. Cortisol-imprinted polymer-coated PGEs (MIP), cortisol-imprinted polymer-coated PGEs with AgNPs (MIP@AgNPs), and nonimprinted polymer-coated PGEs with AgNPs (NIP@AgNPs) were evaluated for sensitive and selective detection of cortisol in aqueous solution. Five different cortisol concentrations (0.395, 0.791, 1.32, 2.64, and 3.96 nM) were applied to the MIP@AgNPs, and signal responses were detected by the DPV with a regression coefficient (R2) value of 0.9951. The modified electrode showed good electrocatalytic activity toward cortisol for the linear concentration range from 0.395 to 3.96 nM, and a low limit of detection was recorded as 0.214 nM. The results indicate that the MIP@AgNPs sensor has great potential for sensitive and selective cortisol determination in biological samples.

Molecularly Imprinted Polymer-Based Sensors for Protein Detection

The accurate detection of biological substances such as proteins has always been a hot topic in scientific research. Biomimetic sensors seek to imitate sensitive and selective mechanisms of biological systems and integrate these traits into applicable sensing platforms. Molecular imprinting technology has been extensively practiced in many domains, where it can produce various molecular recognition materials with specific recognition capabilities. Molecularly imprinted polymers (MIPs), dubbed plastic antibodies, are artificial receptors with high-affinity binding sites for a particular molecule or compound. MIPs for protein recognition are expected to have high affinity via numerous interactions between polymer matrices and multiple functional groups of the target protein. This critical review briefly describes recent advances in the synthesis, characterization, and application of MIP-based sensor platforms used to detect proteins.

Recent Advances in Quartz Crystal Microbalance Biosensors Based on the Molecular Imprinting Technique for Disease-Related Biomarkers

The molecular imprinting technique is a quickly developing field of interest regarding the synthesis of artificial recognition elements that enable the specific determination of target molecule/analyte from a matrix. Recently, these smart materials can be successfully applied to biomolecule detection in biomimetic biosensors. These biosensors contain a biorecognition element (a bioreceptor) and a transducer, like their biosensor analogs. Here, the basic difference is that molecular imprinting-based biosensors use a synthetic recognition element. Molecular imprinting polymers used as the artificial recognition elements in biosensor platforms are complementary in shape, size, specific binding sites, and functionality to their template analytes. Recent progress in biomolecular recognition has supplied extra diagnostic and treatment methods for various diseases. Cost-effective, more robust, and high-throughput assays are needed for monitoring biomarkers in clinical settings. Quartz crystal microbalance (QCM) biosensors are promising tools for the real-time and quick detection of biomolecules in the past two decades A quick, simple-to-use, and cheap biomarkers detection technology based on biosensors has been developed. This critical review presents current applications in molecular imprinting-based quartz crystal microbalance biosensors for the quantification of biomarkers for disease monitoring and diagnostic results.

Preparation of Surface Plasmon Resonance Aptasensor for Human Activated Protein C Sensing

Nucleic acid aptamers are an emerging class of artificial ligands and have recently gained attention in several areas. Here we report the design of a surface plasmon resonance (SPR) aptasensor for highly sensitive and selective sensing of human activated protein C (APC). First, DNA aptamer (DNA-Apt) specific for APC is complexed with N-methacryloyl-L-cysteine (MAC) monomer. Then, 2-hydroxyethyl methacrylate (HEMA) and cyanamide are mixed with the DNA-Apt/MAC complex. The SPR aptasensor is characterized by atomic force microscopy, ellipsometry, and contact angle measurements. Selectivity of SPR aptasensor is carried out in the presence of myoglobin (Myb), hemoglobin (Hb), and bovine serum albumin (BSA). Limit of detection (LOD) and limit of quantification (LOQ) values are 1.5 ng mL^-1 and 5.2 ng mL^-1, respectively. DNA-Apt SPR aptasensor performance for APC detection is also examined in artificial plasma.

Development of an enhanced immunoassay based on protein nanoparticles displaying an IgG-binding domain and luciferase

Detection of small amounts of target molecules with high sensitivity is important for the diagnosis of many diseases, including cancers, and is particularly important to detect early stages of disease. Here, we report the development of a temperature-responsive fusion protein (ELP-DCN) comprised of an elastin-like polypeptide (ELP), poly-aspartic acid (D), antibody-binding domain C (C), and NanoLuc luciferase (N). ELP-DCN proteins form nanoparticles above a certain threshold temperature that display an antibody-binding domain and NanoLuc luciferase on their surface. ELP-DCN nanoparticles can be applied for enhancement of immunoassay systems because they provide more antibody-binding sites and an increased number of luciferase molecules, resulting in an increase in assay signal. Here, we report the detection of human serum albumin (HSA) as a model protein using anti-HSA and ELP-DCN proteins. Upon formation of ELP-DCN nanoparticles, the detection limit improved tenfold compared to the monomeric form of ELP-DCN.

Microfluidic Systems for Cancer Diagnosis and Applications

Microfluidic devices have led to novel biological advances through the improvement of micro systems that can mimic and measure. Microsystems easily handle sub-microliter volumes, obviously with guidance presumably through laminated fluid flows. Microfluidic systems have production methods that do not need expert engineering, away from a centralized laboratory, and can implement basic and point of care analysis, and this has attracted attention to their widespread dissemination and adaptation to specific biological issues. The general use of microfluidic tools in clinical settings can be seen in pregnancy tests and diabetic control, but recently microfluidic platforms have become a key novel technology for cancer diagnostics. Cancer is a heterogeneous group of diseases that needs a multimodal paradigm to diagnose, manage, and treat. Using advanced technologies can enable this, providing better diagnosis and treatment for cancer patients. Microfluidic tools have evolved as a promising tool in the field of cancer such as detection of a single cancer cell, liquid biopsy, drug screening modeling angiogenesis, and metastasis detection. This review summarizes the need for the low-abundant blood and serum cancer diagnosis with microfluidic tools and the progress that has been followed to develop integrated microfluidic platforms for this application in the last few years.

Low-Fouling Substrates for Plasmonic Sensing of Circulating Biomarkers in Biological Fluids

The monitoring of biomarkers in body fluids provides valuable prognostic information regarding disease onset and progression. Most biosensing approaches use noninvasive screening tools and are conducted in order to improve early clinical diagnosis. However, biofouling of the sensing surface may disturb the quantification of circulating biomarkers in complex biological fluids. Thus, there is a great need for antifouling interfaces to be designed in order to reduce nonspecific adsorption and prevent inactivation of biological receptors and loss of sensitivity. To address these limitations and enable their application in clinical practice, a variety of plasmonic platforms have been recently developed for biomarker analysis in easily accessible biological fluids. This review presents an overview of the latest advances in the design of antifouling strategies for the detection of clinically relevant biomarkers on the basis of the characteristics of biological samples. The impact of nanoplasmonic biosensors as point-of-care devices has been examined for a wide range of biomarkers associated with cancer, inflammatory, infectious and neurodegenerative diseases. Clinical applications in readily obtainable biofluids such as blood, saliva, urine, tears and cerebrospinal and synovial fluids, covering almost the whole range of plasmonic applications, from surface plasmon resonance (SPR) to surface-enhanced Raman scattering (SERS), are also discussed.

Molecularly imprinted polymer integrated plasmonic nanosensor for cocaine detection

A molecularly imprinted polymeric nanofilm was prepared for cocaine detection and applied to plasmonic nanosensor for real-time kinetic, selectivity and reusability analyses. The sensing polymeric surface was fabricated by synthesizing a selective and specific nanofilm on the gold plasmonic nanosensor surface. After characterization experiments with atomic force microscopy, ellipsometer, and contact angle measurements, the kinetic studies of cocaine detection in aqueous solutions in a wide concentration range between 0.2-100 μg/mL were applied to plasmonic nanosensor system at 24 °C with a low limit of detection (0.1 μg/L) and quantification values (0.3 μg/L) and the results showed that this molecularly imprinted polymeric nanofilm integrated plasmonic nanosensor is providing a model for the fastest, most accurate and most precise identification of the cocaine molecule which constitutes a large part of the workload of forensic laboratories.