S-Scheme Porphyrin Covalent Organic Framework Heterojunction for Boosted Photoelectrochemical Immunoassays in Myocardial Infarction Diagnosis

Abstract

Cardiac troponin I (cTnI) is an extremely sensitive biomarker for early indication of acute myocardial infarction (AMI). However, it still remains a tough challenge for many newly developed cTnI biosensors to achieve superior sensing performance including high sensitivity, rapid detection, and resistance to interference in clinical serum samples. Herein, a novel photocathodic immunosensor toward cTnI sensing has been successfully developed by designing a unique S-scheme heterojunction based on the porphyrin-based covalent organic frameworks (p-COFs) and p-type silicon nanowire arrays (p-SiNWs). In the novel heterojunction, the p-SiNWs are employed as the photocathode platform to acquire a strong photocurrent response. The in situ-grown p-COFs can accelerate the spatial migration rate of charge carriers by forming proper band alignment with the p-SiNWs. The crystalline π-conjugated network of p-COFs with abundant amino groups also promotes the electron transfer and anti-cTnI immobilizing process. The developed photocathodic immunosensor demonstrates a broad detection range of 5 pg/mL–10 ng/mL and a low limit of detection (LOD) of 1.36 pg/mL in clinical serum samples. Besides, the PEC sensor owns several advantages including good stability and superior anti-interference ability. By comparing our results with that of the commercial ELISA method, the relative deviations range from 0.06 to 0.18% (n = 3), and the recovery rates range from 95.4 to 109.5%. This work displays a novel strategy to design efficient and stable PEC sensing platforms for cTnI detection in real-life serums and provides guidance in future clinical diagnosis.

Novel Porphyrinic Covalent Organic Polymer with Polarity-Switchable Dual Wavelength for Accurate and Sensitive Photoelectrochemical Sensing

“…The photoactive material serving as a light-to-electricity transducer is closely related to analytical performance. − Therein, porphyrinic covalent organic frameworks/polymers (PCOFs/PCOPs) possessing an extended π-conjugated structure have become an attractive candidate for material with ideal photoelectric conversion efficiency owing to its tunable function, excellent stability, and strong light absorption capacity. − So far, numerous PCOFs/PCOPs with high photoelectric conversion efficiency have been developed for PEC biosensing. − Admittedly, the photoactive material with a high photoelectric conversion efficiency has made a significant contribution to improving the PEC sensor sensitivity; however, it is also accompanied by some problems such as wide differences between photoelectrodes and greater susceptibility to interference factors. , And materials like this can only display a single-polarity photocurrent under light excitation, making insufficient accuracy and sensitivity in real sample detection. Therefore, we cast attention to the quest for a photoactive material with multiple characteristics in order to simultaneously give consideration to the sensitivity and accuracy of PEC biosensors.…”

A carbon quantum layer modified BiVO4 photoelectrochemical aptamer biosensor for ultra-sensitive cTnI biomarker detection based on the interface nephelauxetic effect and heterojunction assistance

“…7–9 However, these methods have several limitations during application, for instance a cumbersome procedure, long detection time, and sensitivity limitation. 10 Therefore, it is of significant importance to develop highly sensitive, specific, and rapid methods for cTnI detection, to promote the early diagnosis of AMI.…”