Ultrasensitive detection of gallic acid via triple-synergistic electrochemical sensor modified by β-cyclodextrin-encapsulated and mesoporous silica-embedded graphenized carbon nanotubes networks

To enable the ultrasensitive gallic acid (GA) determination, we aimed to design a multifunctional integrated electrochemical sensor that promoted electron transfer and enriched GA molecules. This work reported an ultrasonic-assisted one-pot preparation of β-cyclodextrin-encapsulated and mesoporous silica-embedded graphenized carbon nanotubes (GRCT@MPS@β-CD), which were employed for the decoration of glassy carbon electrode (GCE). The fabricated GRCT@MPS@β-CD/GCE exhibited outstanding electrochemical response toward GA, achieving a low detection limit of 8.53 nM across the linear range of 0.5–15 μM. Low relative standard deviation values were obtained in repeatability, reproducibility, and anti-interference measurements. When applied to analyze GA in real tea samples, the GRCT@MPS@β-CD/GCE sensor showed satisfactory recovery rates (95.91–103.7 %) and RSD values (1.25–3.84 %). Such excellent GA detection property may be attributed to the synergistic interaction of GRCT@MPS@β-CD. MPS with mesoporous structure could furnish high-density silanol sites that pre-concentrated GA through hydrogen bonding and π–π stacking, and β-CD could promote the enrichment of GA molecules via host-guest inclusion effect. Moreover, β-CD could promote the uniform dispersion of GRCT with high graphitization and excellent electrical conductivity, which established an interconnected carbon conductive networks. This work offers valuable guidance for the design of ultrasensitive GA electrochemical sensors.