Influence of laser and alkali treatment on an Ag/TiO2 nanotube based dopamine sensor

Herein, TiO2 nanotubes (T-NTs) arrays were subjected to two types of treatment followed by a simple metal deposition technique to significantly enhance the performances of T-NTs based electrochemical sensing of dopamine. The first type of treatment was done by soaking T-NTs in sodium hydroxide solution for an optimal time to enhance the conductivity and charge carrier density. The second type of treatment employed was laser irradiation, which induces crystallinity disorder and forms rutile TiO2, promoting active analyte adsorption sites. Afterward, silver (Ag) was electro-deposited on the T-NTs as a dopamine sensing catalyst to form T-NTs/Ag nanohybrids. The dual-treated T-NTs based sensor showed 3-fold enhancement in sensitivity (from 8.2 mu A mM(-1) cm(-2) to 32 mu A mM(-1) cm(-2)), reduced charge transfer resistance (from 38 x 10(-6) omega to 0.7 x 10(-6) omega), above 2 order higher donor charge density (from 3.58 x 10(18) cm(-3) to 1.41 x 10(21) cm(-3)), and reduced limit of detection (from 32.3 mu M to 2.8 mu M) in comparison to plain T-NTs based sensor. In addition, the sensitivity reported here is significantly higher than most of the previously reported TiO2 based dopamine sensors. Perspective-wise, the dual treatment approach is a promising technique and is highly desirable for enhancing the performances of T-NTs and other nanomaterial based electrochemical sensors.

Automated summary

In this study, TiO2 nanotubes were improved through two types of treatments to enhance the sensitivity and performance of dopamine electrochemical sensors. The dual-treated TiO2 nanotubes exhibited significantly improved sensitivity, reduced charge transfer resistance, increased carrier density, and lowered detection limit compared to plain TiO2 nanotubes sensors. The dual treatment approach shows promise for enhancing the performance of TiO2 nanotubes and other nanomaterial based electrochemical sensors.