Dual recognition electrochemical sensor for detection of gallic acid in teas, apples and grapes and derived products

Sensitive determination of gallic acid (GA) is important for food quality control due to its numerous bioactivity. This study presented an electrochemically deposited method for constructing poly(3-aminophenylboronic acid)-poly(β-cyclodextrin)/carboxylated multi-walled carbon nanotubes-chitosan (PAPBA-Poly(β-CD)/cMWCNT-CS) nanocomposites modified electrode. The cMWCNT-CS materials and PAPBA-Poly(β-CD) copolymer were utilized for signal amplification and dual recognition of GA, respectively. Electrochemical detection of GA was achieved through the peak current change of potassium ferricyanide redox probe induced by the synergistic interaction of PAPBA-Poly(β-CD) with target molecules. The proposed method exhibited an ultra-low limit of detection of 0.16 fM and ultra-wide response range of 10 fM to 10 μM for GA with the superiorities of easy construction, rapid response, good reproducibility, and excellent selectivity. This method could be employed to test GA concentration in black teas, apples, grapes, grape beverage, and wine samples, which provided an alternative method for ultrasensitive analysis of functional components in actual samples.