Enzymatic Electrochemical Biosensor from Eu-Doped SnO2 Embedded in MXene for High Performance Sensing Lactate

In this work, Eu3+-doped SnO2 nanoparticles are prepared and embedded into MXene (Ti3C2) laminates, and Ti3C2@Eu-SnO2 composites are obtained. Cyclic voltammetry (CV) and scanning electron microscopy (SEM) characterization show that the composites have excellent electrochemical properties and unique morphology. The electrochemical impedance spectroscopy (EIS) and Fourier transform infrared spectrometer (FTIR) results of lactate oxidase (Lox) immobilized on Ti3C2@Eu-SnO2 indicate that Eu-SnO2, Ti3C2, and Lox have a good hybrid coordination and biocompatibility. The enzymatic electrochemical biosensor constructed with Ti3C2@Eu-SnO2/Lox on glassy carbon electrode (GCE) reveals an excellent linear relationship in the lactate concentration ranging from 1.0x10(-9) to 1.0x10(-4) mol L-1. It has a low detection limit of 3.38x10(-10) mol L-1 and high sensitivity of 4.815 mA nmol(-1) L cm(-2). Furthermore, the fabricated biosensor has a reasonable recovery rate for determining lactate in human serum.

Automated summary

Eu3+-doped SnO2 nanoparticles are embedded into MXene laminates to obtain Ti3C2@Eu-SnO2 composites with excellent electrochemical properties and unique morphology. The composites show good hybrid coordination and biocompatibility, making them suitable for lactate detection. The constructed biosensor exhibits a linear relationship, low detection limit, high sensitivity, and reasonable recovery rate for lactate determination.