Methylene blue-loaded Nanocomposites based SERS immunoassay sensor for highly sensitive NMP22 detection

Bioinspired Core-shell nanospheres integrated in multi-signal immunochromatographic sensor for high throughput sensitive detection of Bongkrekic acid in food

Cortisol, a steroid hormone, is a main biomarker of psychological stress. Early diagnosis and proper treatment of such stress is crucial to prevent the excessive secretion of cortisol. However, cortisol has a low molecular weight and cannot provide sufficient recognition sites for sandwich immunoreaction; it has previously been measured using a competitive immunoassay instead of a general sandwich immunoassay. The disadvantage of this approach is that quantitative measurements are limited because of the narrow measurable range that is key for biosensors. To overcome this limitation, we propose a new detection platform that enables small molecules such as cortisol to be quantified with high detection sensitivity. A trap lateral flow immunoassay (trapLFI) sensor has deletion and detection zones instead of the test and control zones in general lateral flow immunoassay (LFI) sensors. The conjugates used to minimize possible detection targets at low concentration are gold nanoparticles that include an antibody against cortisol and an enzyme for signal generation. Target-bound conjugates are captured in the detection zone, whereas conjugates not binding with targets are trapped in the deletion zone. Using this platform, enzyme-catalyzed color signals increase in the detection zone and decrease in the deletion zone with the concentration of cortisol. The ratio of signal from deletion zone and detection zone supplied a wide analytical range (0.01-100 ng mL-1) with high detection sensitivity (9.9 pg mL-1). Analysis of 15 human saliva samples showed a good correlation with conventional ELISA results (R2 = 0.9432).

A simple optical fiber sensor based on localized surface plasmon resonance was constructed for direct and rapid measurement of thyroglobulin (Tg). Specific tests for Tg in patients that have undergone thyroidectomy are limited because of insufficient sensitivity, complicated procedures, and in some cases, a long time to yield a result. A sensitive, fast, and simple method is necessary to relieve the psychological and physical burden of the patient. Various concentrations of Tg were measured in a microfluidic channel using an optical fiber sensor with gold nanoparticles. The sensor chip has a detection limit of 93.11 fg/mL with no specificity for other antigens. The potential applicability of the Tg sensing system was evaluated using arbitrary samples containing specific concentrations of Tg. Finally, the sensor can be employed to detect Tg in the patient’s serum, with a good correlation when compared with the commercial kit.

A programmable multichannel chemiluminescence immunoassay sensor for automatic quantification of the total amount of fumonisin B1, B2 and B3.

Quantitative analysis of thyroid-stimulating hormone (TSH) using SERS-based lateral flow immunoassay

Highly sensitive detection of the hepatotoxin microcystin-LR by surface modification and bio-nanotechnology

Pesticide residues pose significant risks to human health and the environment, emphasizing the need for sensitive detection and analysis methods. Fluorescence-based sensors, particularly those utilizing aggregation-induced emission (AIE) fluorophores (AIEgens), have demonstrated exceptional performance in this area. This review summarizes key advancements in pesticide detection sensors based on AIEgens, detailing their luminescence mechanisms and fluorescence sensing principles. It explores various applications of AIEgens in fluorescence sensors, including organic small-molecule sensors, nanocomposite sensors, metal-organic framework sensors, supramolecular sensors, fluorescent porous organic polymer sensors, and lateral flow immunoassay sensors, with specific examples illustrating their detection mechanisms and performance. This review also discusses current challenges and future perspectives for the development of these sensors. We anticipate that this review will serve as a valuable and timely resource for researchers working to advance the development and application of AIEgens-based sensors in pesticide detection.

We report an agglutination-based immunosensor for the quantification of C-reactive protein (CRP). The developed immunoassay sensor requires approximately 15 minutes of assay time per sample and provides a sensitivity of 0.5 mg/L. We have measured the capacitance of interdigitated electrodes (IDEs) and quantified the concentration of added analyte. The proposed method is a label free detection method and hence provides rapid measurement preferable in diagnostics. We have so far been able to quantify the concentration to as low as 0.5 mg/L and as high as 10 mg/L. By quantifying CRP in serum, we can assess whether patients are prone to cardiac diseases and monitor the risk associated with such diseases. The sensor is a simple low cost structure and it can be a promising device for rapid and sensitive detection of disease markers at the point-of-care stage.