A point-of-care chemiluminescence immunoassay for pepsinogen I enables large-scale community health screening

An automatic and smart platform for rapid detection of cadmium and lead simultaneously in rice using triple-amplified chemiluminescence immunoassay

Rapid detection of trace ions is urgently needed for large-scale screening to ensure food safety. This study developed an innovative and automatic strategy, based on a smart-designed platform for rapid detection of cadmium and lead in rice. As bridge antibody, the antigen was conjugated with goat anti-mouse immunoglobulin G labeled alkaline phosphatase. Meanwhile, a biotin-streptavidin system was introduced to micromagnetic particles, thus providing a triple-amplified chemiluminescence immunoassay with high sensitivity, accuracy and specificity. The limits of detection for cadmium and lead were 0.06 and 1.00 ng mL-1, respectively, within 30 min. The recoveries ranged from 89.81 to 114.92 %, with relative standard deviations less than 9.2 %. The results obtained agreed with those of inductively coupled plasma-mass spectrometry and certified reference materials. Additionally, the auto-operation avoided human errors as well as being convenient, fast, automatic and high-throughput. Therefore, this smart platform can be applied for large-scale Cd2+ and Pb2+ screening.

Ultrasensitive fluorescence immunoassay of pepsinogen I based on enzyme-triggered decomposition of AuNCs/MnO2

Gastric cancer is a prevalent malignant tumor of the gastrointestinal tract accompanied by a high mortality rate; therefore, early gastric cancer screening is critical for improving patient survival. In this study, we present a facile fluorescence immunoassay for highly sensitive screening of pepsinogen I (PG I) based on a one-pot biomimetic mineralization process for the synthesis of gold nanocluster-anchored manganese dioxide (AuNCs/MnO2) nanosheets. MnO2 first quenches the fluorescence of AuNCs through the Förster resonance energy transfer effect, whereas the introduction of ascorbic acid (AA) leads to the decomposition of MnO2 and rapidly recovers the fluorescence of AuNCs. Based on the above principles and phenomena, we developed a sensitive fluorescence immunoassay for the in situ generation of AA to detect PG I. Specifically, in the presence of PG I, the sandwich-type immunoreactivity-enriched alkaline phosphatase-labeled secondary antibody catalyzes the production of AA from the substrate, which enhances the fluorescence intensity. Under optimized conditions, the fluorescence intensity increased linearly with the concentration of PG I (0.05 to 200 ng mL-1) with a limit of detection (LOD) of 0.013 ng mL-1 (S/N = 3). The designed sensing platform has good stability (more than one year) and excellent anti-interference capability and demonstrates satisfactory accuracy for detection in real samples compared to commercial ELISA kits.

Advances in point-of-care genetic testing for personalized medicine applications

Breakthroughs within the fields of genomics and bioinformatics have enabled the identification of numerous genetic biomarkers that reflect an individual's disease susceptibility, disease progression, and therapy responsiveness. The personalized medicine paradigm capitalizes on these breakthroughs by utilizing an individual's genetic profile to guide treatment selection, dosing, and preventative care. However, integration of personalized medicine into routine clinical practice has been limited-in part-by a dearth of widely deployable, timely, and cost-effective genetic analysis tools. Fortunately, the last several decades have been characterized by tremendous progress with respect to the development of molecular point-of-care tests (POCTs). Advances in microfluidic technologies, accompanied by improvements and innovations in amplification methods, have opened new doors to health monitoring at the point-of-care. While many of these technologies were developed with rapid infectious disease diagnostics in mind, they are well-suited for deployment as genetic testing platforms for personalized medicine applications. In the coming years, we expect that these innovations in molecular POCT technology will play a critical role in enabling widespread adoption of personalized medicine methods. In this work, we review the current and emerging generations of point-of-care molecular testing platforms and assess their applicability toward accelerating the personalized medicine paradigm.

Painless and sensitive pepsinogen I detection: an electrochemical immunosensor based on rhombic dodecahedral Cu3Pt and MoS2 NFs

Gastric cancer (GC) is a common malignant tumour of the digestive tract with a high mortality rate worldwide. However, many patients delay treatment due to the avoidance of the costly and painful procedure of gastroscopy. Therefore, an early convenient screening method is essential to improve the survival rate of GC patients. To address this issue, we constructed an electrochemical immunosensor supported by rhombohedral Cu₃Pt and MoS₂ nanoflowers (MoS₂ NFs) for rapid, painless and quantitative detection of the GC biomarker in vitro. Here, pepsinogen I was employed as a model protein biomarker to analyse the performance of the immunosensor. The rhombohedral dodecahedral Cu₃Pt nanoparticles decorated with MoS₂-NFs were further functionalized; this allowed the constructed sensor to possess more nano- or micro-structures, thereby improving the detection sensitivity. In specific applications, the corresponding bioactive molecules can be flexibly captured. Under optimal conditions, the immunoassay showed a wide linear range from 500 pg mL^-1 to 400 ng mL^-1 and a low detection limit of 167 pg mL^-1 (S/N = 3). This covers the critical value of 70 ng mL^-1, and the results obtained from the analysis of human serum samples were on par with those from the enzyme immunoassay, suggesting significant potential for this new method in daily diagnosis.

Detection of Carbohydrate Antigen 50 Based on a Novel Miniaturized Chemiluminescence Analyzer Enables Large-Scale Cancer Early Screening in Grassroots Community

Early screening of cancer can effectively prolong survival time and reduce cancer mortality. However, the existing health-monitoring devices can only be carried out in professional laboratories, so large-scale early cancer screening in resource-limited settings is hardly achieved. To embrace the challenge, we developed a novel chemiluminescence immunoassay (CLIA) analyzer that does not require a professional operation. Then, it was applied to detect carbohydrate antigen 50 (CA50), a non–organ-specific tumor marker for screening various cancers. As a result, the analyzer exhibited excellent performance that the total assay time was only 15 min, and the detection limit reached 0.057 U ml⁻¹. A coefficient of variance (CV) less than 15% was well-controlled for both intra- and inter-assay precision, and the linear range was 0–500 U ml⁻¹. More importantly, this analyzer can continuously detect 60 samples per hour without any professional paramedic. Finally, this analyzer has been applied to evaluate clinical samples and the detected results showed a good correlation with the clinical test results (correlation coefficient, 0.9958). These characteristics exactly meet large-scale and high-throughput early screening of cancer. Thus, this miniaturized analyzer for CA50 detection is promising to achieve early large-scale screening of cancer in the resource-limited grassroots community.