Point-of-Care Immunoassay Based on a Multipixel Dual-Channel Pressure Sensor Array with Visual Sensing Capability of Full-Color Switching and Reliable Electrical Signals

Abstract

The point-of-care (POC) method with affordability and portability for the sensitive detection of biological substances is an emerging topic in rapid disease screening and personalized medicine. In this work, we demonstrated a diverse responsive platform based on a dual-channel pressure sensor (DCPS). The DCPS had a multilayer flexible architecture consisting of a photonic hydrogel with chromatic transitions and a piezoresistive pressure sensor as the electrical data transmission unit, both of which had the property of pressure-induced mechanical stimulus feedback. By incorporating a platinum nanoparticles-labeled detection antibody (PtNPs-dAb) into the sandwich-type immunoreaction for the target carcinoembryonic antigen (CEA, as a model analyte), gas decomposition could be triggered by the addition of hydrogen peroxide (H2O2) to induce a significant increase under pressure in a closed chamber. Meanwhile, the DCPS enabled an accurate electrical signal output, and the photonic hydrogel converted spatiotemporal stimuli into eye-readable colorations with string brilliance. In this way, the target concentration could be quantificationally related to the electrical response and intuitively perceived through visible color alterations. Under optimal conditions, a sensitive determination of CEA was performed in a detectable range of 0.3–60 ng/mL with a limit of detection (LOD) of 0.13 ng/mL. In addition, the proposed protocol had satisfactory selectivity, accuracy, and reproducibility. Furthermore, an array-based immunoassay device was fabricated to conceptually validate its application potential in high-throughput biomedical detection and inspire a dual-signal POC diagnostic platform in a friendly way for resource-limited settings.

Metal–Organic Framework-Mediated Bioorthogonal Reaction to Immobilize Bacteria for Ultrasensitive Fluorescence Counting Immunoassays

“…Point-of-care testing (POCT) provides immediate and reliable diagnostic results out of the laboratory and plays an important role in individual disease monitoring and health care. − In this context, we designed and fabricated a smartphone device based on FBCIA, enabling automatic bacteria counting and result output, for potential point-of-care detection of protein biomarkers. The device mainly consists of four components incorporated into a three-dimensional (3D) printed case (Figure a): (i) a wet-etched glass slide consisting of 10 microwells to contain detection reagent; (ii) an light-emitting diode (LED) light source emitting light of 488 nm; (iii) a microscopic system consisting of an objective lens, an optical bandpass filter that transmits light over 525 nm, and an ocular lens; and (iv) a smartphone (iPhone SE) equipped with a homemade application (Figure b) for image capture and processing.…”

Recent advances in metal–organic framework-based photoelectrochemical and electrochemiluminescence biosensors

“…Additionally, there is a growing demand for portable devices in many fields, such as rapid screening of infectious diseases, environmental monitoring, and food safety inspection. [159][160][161][162][163][164] However, MOFbased PEC and ECL biosensors are often not portable enough to meet the needs of point of care testing. To meet this unique need, combining MOF-based PEC and ECL biosensors with microfluidic technology would be an effective solution.…”

Ultrasensitive electrochemical immunoassay for screening the influenza A (H1N1) virus based on atomically Ru-dispersed nitrogen-doped carbon

“…The detection results are tabulated in Table 2. Obviously, all t exp values were below 2.78 (t crit[0.05,4] = 2.78), [29][30][31][32][33][34] thereby revealing the strong reliability of the Ru-CN-SPCEbased electrochemical immunoassay.…”