Dense Conductive Metal–Organic Frameworks as Robust Electrocatalysts for Biosensing

Abstract

Due to the fascinating properties such as high porosity, large surface areas, and tunable chemical components, metal–organic frameworks (MOFs) have emerged in many fields including catalysis, energy storage, and gas separation. However, the intrinsic electrical insulation of MOFs severely restricts their application in electrochemistry. Here, we synthesize a series of 2D conductive MOFs (cMOFs) through tuning the structure with atomic precision using simple hydrothermal methods. Various electroactive probes are used to reveal the structure–property relationships in 2D cMOFs. Then, we demonstrate the first exploration and implementation of 2D cMOFs toward the construction of electrochemical biosensors. In particular, the biosensor based on Cu3(tetrahydroxy-1,4-quinone)2 [Cu3(THQ)2] displays a remarkably improved electrocatalytic performance at a much lower potential. The mechanism study reveals the essential role of charge-transfer interactions between the dense catalytic sites of Cu3(THQ)2 and analytes. Furthermore, the Cu3(THQ)2-based biosensor demonstrates robust anti-interference capability, good stability, fast response speed, and an ultralow detection limit for paraoxon. These promising results indicate the great potential of cMOFs in biomedical, food safety, and environmental sensing applications.

Ultrasensitive Dual-Mode Visual/Photoelectrochemical Bioassay for Antibiotic Resistance Genes through Incorporating Rolling Circle Amplicons into a Tailored Nanoassembly

“…32 The other peak at 1621 cm −1 corresponded to C�O in polyvinylpyrrolidone, which was introduced during CuONFs fabrication process. 15,33 As for NH 2 −CuONFs (curve b), two new adsorption peaks near 2928 and 2863 cm −1 represented the stretching vibration of C−H of amination reagent (APTES). Two enhanced peaks were observed at 1550 and 1656 cm −1 , respectively, corresponding to N−H stretch in APTES, implying the successful preparation of NH 2 −CuONFs.…”

Synthesis of Conductive MOFs and Their Electrochemical Application

“…Finally, tunable active centers enable the selective detection of target analytes. [237,239] Currently, research on the sensing performance of conductive MOFs mainly focuses on selectivity, sensitivity, and response speed.…”

“…developed a Cu‐THQ‐based sensor with an ultra‐low detection limit for paraoxon and revealed the structure‐property relationship of Cu‐THQ. [ 239 ] The research found that compared to other conductive MOF‐based sensors, the Cu‐THQ‐based sensor exhibited significantly improved electrocatalytic performance at lower potentials. Mechanistic investigations revealed that this enhanced electrocatalytic performance can be attributed to more efficient charge transfer interactions between the dense catalytic sites of Cu‐THQ and the analyte.…”

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

“…Fabrication of the PEC Biosensor. First, the pretreated glassy carbon electrode (GCE) 31 was dipped into 0.25% (w/v) HAuCl 4 for electrostatic deposition of gold nanoparticles (depAu). Then, 10 μL of 2 μM HP was dropped onto the GCE and incubated at 4 °C for 12 h. Following that, hexanethiol (HT, 10 μL of 0.1 mM) was reacted for 40 min to block the nonspecific reaction sites.…”