Smartphone-Based Photoelectrochemical Immunoassay with Co ₉ S ₈ @ZnIn ₂ S ₄ for Point-of-Care Diagnosis of Breast Cancer Biomarker

Abstract

Photoelectrochemical immunoassays incorporating specific antigen-antibody recognition reactions with the photon-electron conversion capabilities of photocatalysts have been developed for biomarker detection, but most involve bulky and expensive equipment and are unsuitable for point-of-care testing. Herein, a portable smartphone-based photoelectrochemical immunoassay was innovatively designed for the on-site detection of breast cancer biomarkers (human epidermal growth factor receptor 2; HER2). The system consists of a split-type immunoassay mode, disposable screen-printed electrode covered with hierarchical Co9S8@ZnIn2S4 heterostructures, an integrated circuit board, and a Bluetooth smartphone equipped with a specially designed app. Using alkaline phosphatase (ALP) catalytic strategy to in situ generate ascorbic acid (AA) for electron-donating toward Co9S8@ZnIn2S4 heterostructures, an immunoreaction was successfully constructed for the HER2 detection in the real sample due to the positive correlation of the photocurrent signal to electron donor concentration. Differential charge density indicates that the formation of Co9S8@ZnIn2S4 heterojunction can facilitate the flow of charges in the interface and enhance the photocurrent of the composite. More importantly, the measured photocurrent signal can be wirelessly transmitted to the software and displayed on the smartphone screen to obtain the corresponding HER2 concentration value. The photocurrent values linearly with the logarithm of HER2 concentrations range spanned from 0.01 ng/mL to 10 ng/mL with a detection limit of 3.5 pg/mL. Impressively, the clinical serum specimen results obtained by the proposed method and the wireless sensing device are in good agreement with the enzyme-linked immunosorbent assay (ELISA).

Cation Exchange Reaction-Mediated Photothermal and Polarity-Switchable Photoelectrochemical Dual-Readout Biosensor

“…As a biodetection with the capability of interfacing biomolecular recognition processes and photocurrent responses that rely on electron or hole transfer in photocatalysts and electrodes, photoelectrochemical (PEC) bioanalysis possesses the advantages of excellent sensitivity, low background, and ease of miniaturization. − Up to now, PEC bioanalysis has achieved significant advancements; however, most PEC biosensors reported rely on the conventional “signal-on” or “signal-off” principle in terms of PEC response patterns, which are restricted by false-positive or false-negative signals attributing to possible oxidative or reductive interferences. − Recently, a novel PEC biosensing platform with a polarity-switchable mechanism has been investigated to improve the accuracy, reliability, and anti-interference ability of analytical strategies. , For instance, our group developed a PEC platform based on a photocurrent-polarity-switching strategy induced by modulating the positional configuration of methylene blue and ferrocene for a highly sensitive assay of microRNA-21 . Fu et al constructed an iron phthalocyanine-mediated polarity-switchable PEC sensing system for selective detection of As­(V) .…”

Endogenous Protease-Activatable Nanosensor Based on PNA–Peptide–DNA Engineering for AND-Gated and Dual-Model Detection of MicroRNA in Single Living Tumor Cells

“…Tumor microenvironmental interactions can positively or negatively regulate tumor survival, proliferation, and progression; 1 therefore, the development of rapid and sensitive analytical methods to detect disease markers within tumors is essential. 2,3 In particular, cathepsin B (CaB) protease is a type of endogenous enzyme found in lysosomes, and the expression levels of proteases have been found to be abnormally upregulated in a variety of tumor cells. 4,5 It can promote the proliferation of tumor blood vessels and enhance the operation ability of tumor cells.…”

“…Tumor growth and metastasis are the leading causes of cancer-related deaths worldwide. Tumor microenvironmental interactions can positively or negatively regulate tumor survival, proliferation, and progression; therefore, the development of rapid and sensitive analytical methods to detect disease markers within tumors is essential. , In particular, cathepsin B (CaB) protease is a type of endogenous enzyme found in lysosomes, and the expression levels of proteases have been found to be abnormally upregulated in a variety of tumor cells. , It can promote the proliferation of tumor blood vessels and enhance the operation ability of tumor cells. Furthermore, microribonucleic acids (miRNAs) are a class of small endogenous nonprotein coding RNAs that are ubiquitously involved in the regulation of gene expression and multiple biological processes including cell differentiation and apoptosis. − The expression levels and subcellular distribution of miRNAs are closely related to the growth and differentiation of tumor cells. , Therefore, the growth and expression of these two pro-metastatic biomolecules, CaB protease and miRNAs, would not only allow one to comprehend their physiological and pathological effects but also provide insight into tumor metastasis and further diagnosis.…”

Smartphone-based portable photoelectrochemical biosensing system for point-of-care detection of urine creatinine and albumin

“…24–27 Through the miniaturized design of the excitation light source and the working circuit, efforts have been devoted to developing portable PEC detection devices with the smartphone for biomolecule analysis. 28,29 Due to the ability to provide low irradiation energy, low-power light-emitting diodes (LEDs) are employed to replace xenon lamps as the excitation source for photoactive semiconductor materials during the PEC detection. 30–32 Meanwhile, the two-dimensional photoactive material graphitic carbon nitride (g-C 3 N 4 ) with a proper bandgap of 2.7 eV is considered as an excellent visible-light-driven photocatalyst.…”