Fabrication of gallic acid electrochemical sensor based on interconnected Super-P carbon black@mesoporous silica nanocomposite modified glassy carbon electrode

Abstract

The efficient and accurate detection of gallic acid (GA) is particularly important for human health. Herein, a simple and low-cost ultrasonic-assisted strategy was proposed for the preparation of multifunctional nanocomposite of Super-P carbon black (SPCB) nanoparticles and mesoporous silica nanoparticles (MSNs), which was used to modify the glassy carbon electrode (GCE) for the fabrication of GA electrochemical sensor (SPCB@MSNs/GCE). SPCB with pearl-chain nanostructure presented an interconnected highly conductive carbon network, which significantly improved the charge transfer efficiency. MSNs with spherical morphology and mesoporous structure exhibited uniform particle dispersion and high active surface area, which remarkably improved the surface accumulation effect of sensing electrode towards GA. Moreover, the excellent electrical conductivity of SPCB compensated for the non-conductive property of MSNs. Under the optimized condition, the electrochemical response of SPCB@MSNs/GCE sensor had a good linear relationship with GA concentration (0.5–10 μM), and the corresponding limit of detection could reach up to 4.911 nM. The fabricated nanohybrid sensor showed good reproducibility, repeatability and anti-interference property. Moreover, the satisfactory GA recoveries and RSD values were achieved for the electrochemical detection of GA in tea samples. This work provides an important reference for the highly sensitive analysis of GA in the field of food safety.