Design of a Double-Photoelectrode Sensing System with a Metal–Organic Framework-Based Antenna-like Strategy for Highly Sensitive Detection of PD-L1

Abstract

Currently, the construction of heterojunctions as a method to enhance photoelectrochemical (PEC) activity has shown prospective applications in the analytical field. Restricted by carrier separation at the interface, developing a heterojunction sensing platform with high sensitivity remains challenging. Here, a double-photoelectrode PEC sensing platform was fabricated based on an antennalike strategy by integrating MIL-68(In)−NH 2 , a p-type metal−organic framework (MOF) photocatalyst, as a photocathode with the type-II heterojunction of CdSe/ MgIn 2 S 4 as a photoanode synchronously. According to the ligand-to-metal charge transition (LMCT), the photo-generated carriers of MIL-68(In)−NH 2 transferred from the organic ligand to the metal cluster, which provides an efficient antennalike transfer path for the charge at the heterojunction interface. In addition, the sufficient Fermi energy difference between the double photoelectrode provides the continuous internal driving force required for rapid carrier separation at the anode detection interface, significantly improving the photoelectric conversion efficiency. Hence, compared with the traditional heterojunction single electrode, the photocurrent response of the double-photoelectrode PEC sensing platform developed using the antenna-like strategy is 2.5 times stronger. Based on this strategy, we constructed a PEC biosensor for the detection of programed death-ligand 1 (PD-L1). The elaborated PD-L1 biosensor exhibited sensitive and precise detection capability with a detection range of 1 × 10 −5 to 1 × 10 3 ng/mL and a lower detection limit of 3.26 × 10 −6 ng/mL and demonstrated the feasibility of serum sample detection, providing a novel and viable approach for the unmet clinical need of PD-L1 quantification. More importantly, the charge separation mechanism at the heterojunction interface proposed in this study provides new creative inspiration for designing sensors with high-sensitivity PEC performance.

Dual regulation of hierarchical porosity and heterogeneous interfaces in Cu-BTC/Bi2MoO6 for thermally-driven and UV-light-activated selective acetone sensing

“…17 The architecting of heterogeneous MOF heterostructures has proven to be a feasible strategy for realizing extraordinary gas-sensitive performance through optimizing the interfacial charge transport efficiency and introducing specic close-contact interfaces. 18,19 Therefore, it is anticipated that introducing defect-rich porous structures in the MOF matrix, accompanied by the construction of a highquality heterogeneous interface will jointly enhance the sensitivity, reduce detection limits and extend the device lifetimes of MOF-based sensors.…”

A digital microfluidic device integrated with electrochemical sensor and 3D matrix for detecting soluble PD-L1

“…For example, electrochemical sensors can detect sPD-L1 levels in whole blood, where sPD-L1 molecules were first captured on gold-coated magnetic nanoparticles as “dispersible electrodes” in regular tubes and achieved a detection limit of 15 aM within 15 min ( Moazzam et al, 2021 ). Very recently, photonic methods have also been combined with electrochemical sensors to create photo-electrochemical sensing systems that can detect femtograms of sPD-L1 molecules ( Li et al, 2023 ; Wang et al, 2023 ). While these new methods offer superior sensitivity in detection, each of the processes, including sample preparation, sample wash and target detection, are typically performed as distinct steps in regular tubes.…”

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.…”