A metal–organic framework with multienzyme activity as a biosensing platform for real-time electrochemical detection of nitric oxide and hydrogen peroxide

Abstract

A Metal–Organic Framework (MOFs) with large surface area, exposed active site, excellent catalytic performance and high chemical stability has been used as an artificial enzyme and designed for nonenzymatic electrochemical sensors. Here, a strategy of using an enhanced electrochemical sensing platform for the detection of nitic oxide (NO) and hydrogen peroxide (H₂O₂) was designed via a nano-metalloporphyrinic metal–organic framework (NporMOF(Fe)) as an electrode material. By taking advantage of the small size, high surface area and exposed Fe active site, the obtained NporMOF(Fe) displays excellent electrocatalytic activity toward NO and H₂O₂. The NporMOF(Fe) modified electrode shows high sensing ability toward the in situ generated NO in NO₂⁻ containing phosphate buffer (PB) solution with a wide linear detection range of 5 μM to 200 μM and a very low detection limit of 1.3 μM. Moreover, NporMOF(Fe) exhibits high electrocatalytic activity toward the reduction of H₂O₂ and the practical detection of H₂O₂ released from HeLa cells. Furthermore, the NporMOF(Fe) modified electrode shows excellent selectivity toward the detection of NO and H₂O₂ in the presence of other physiologically important analytes. This method shows excellent biosensing performance, implying the universal applicability of MOFs-based artificial nanozymes for biosensors and the potential application for third generation biosensors.