Zinc–Air Battery-Assisted Self-Powered PEC Sensors for Sensitive Assay of PTP1B Activity Based on Perovskite Quantum Dots Encapsulated in Vinyl-Functionalized Covalent Organic Frameworks

Abstract

The self-powered sensors have attracted widespread attention in the analysis field due to a huge demand of point-ofcare testing (POCT) in the early diagnosis of diseases. However, the output voltage of the reported self-powered sensors is always small, resulting in a narrow linear detection range and low assay sensitivity. Herein, a self-powered photoelectrochemical (PEC) sensor with zinc−air batteries as a power source was developed for activity assay of protein tyrosine phosphatase 1B (PTP1B) based on perovskite quantum dots encapsulated in the vinyl-functionalized covalent organic framework (COF-V). CsPbBr 3 nanocrystals were stabilized by the confinement effect of the COF-V cage without aggregation, and the resulting CsPbBr 3 @COF-V composite was used as the cathodic photoelectric material to construct the zinc−air battery with a large open-circuit voltage (OCV, 1.556 V). Before PTP1B activity assay, an auxiliary peptide− polyamidoamine−phosphopeptide (P2-PAMAM-P1) hybrid was introduced into the photocathode via thiol−ene click reaction between the thiol group on the P1 and the vinyl group on the COF-V. The steric hindrance effect of the P1-PAMAM-P2 hybrid inhibited the PEC performance of the photocathode, resulting in a small OCV of the zinc−air battery. When the PTP1B existed, PTP1B-catalyzed dephosphorylation of tyrosine on P1 facilitated the cleavage process of P1 by chymotrypsin, leading to the removal of the P2-PAMAM-P1 hybrid from the photocathode and consequently the enhancement of the OCV. Therefore, the activity of PTP1B was sensitively detected. The developed self-powered PEC sensor showed superior performance for PTP1B activity assay (broad linear response range, 0.1 pM to 10 nM and low detection limit, 0.032 pM) due to the large output voltage of the constructed zinc−air battery and has great potential in POCT of protein phosphatase-related diseases and the discovery of protein phosphatasetargeted drugs.

Dually Amplified Electrochemical Aptasensor for Endotoxin Detection via Target-Assisted Electrochemically Mediated ATRP

“…The basic principle of the electrochemical aptasensor for endotoxin detection is illustrated in Scheme . The recognition interface was constructed through the sequential self-assembly of the end-thiolated aptamer receptor and a MCH layer, in which the aptamer receptor was applied to selectively capture endotoxin, while the MCH layer was used to block nonspecific adsorption, , suppress background current, and project aptamer receptors into the solution to facilitate aptamer-endotoxin binding . According to the surface plasmon resonance (SPR) measurement, the end-tethered aptamer receptor can be featured by a dissociation constant ( K d ) of 38 nM to endotoxin, indicating that it is applicable to endotoxin detection on the electrode surface with high specificity and affinity .…”

Metal Porphyrin Complex Combined with Polymerization and Isomerization Cyclic Amplification for a Sensitive Photoelectrochemical Assay

“…Cathode photoactive materials, such as poly­(3-hexylthiophene-2,5-diyl) (P3HT) and poly­(2,5-dimercaptothiadiazole-triazine), have attracted extensive attention in the construction of highly sensitive and accurate PEC detection systems, due to their capability to resist the interference of reductive substances. − However, to the best of our knowledge, most of their molecular formulas are complex and restricted to volatile organic solvents, − which are prone to generate unrepeatable photocurrent, thereby restraining their application to only serve as platforms to construct the signal-off biosensors liable to produce an intrinsic false-positive signal. − More importantly, the photoelectric conversion efficiency is expected to be further improved. Accordingly, exploring simple, readily accessible, and biocompatible photoelectric materials with high photoelectric conversion efficiency is necessary and challenging.…”

Preparation of CH3NH3PbBr3 Perovskites Encapsulated in ZIF-8 with Improved Stability and Their Application in Fluorimetry and Information Encryption

“…As an emerging class of network materials, metal organic frameworks (MOFs) are formed by metal-based nodes and multidentate ligands. They not only show regular pore structure and ultrahigh specific surface area but also possess tunable size and a controllable structure. , Due to their diversity and adjustability, MOFs are a satisfactory choice for the development of new composites, which can isolate nanomaterials from each other and protect them from the erosion of the external environment. − …”