Dual-Signal Colorimetric and Electrochemical Sensor of Dopamine Based on Nanocomposite of Cobalt Oxyhydroxide/Carbon Black

Abstract

In this report, a novel electrochemical and colorimetric dual-mode sensing system was developed for the sensitive and selective detection of DA. The large surface area of CoOOH and the excellent conductivity of CB endow the electrochemical sensing system with high sensitivity. CoOOH with oxidase-like activity will convert the colorless TMB into the blue oxidation product OXTMB, appearing an absorption peak at 652 nm correspondingly. And the addition of DA will inhibit the activity of oxidase followed by a reducing in the absorption. The proposed method provided a wider detection range for DA from 1 to 30 μM and 1 to 950 μM through colorimetric and electrochemical methods, respectively. Furthermore, this biosensor with good biocompatibility has been successfully used for tracking of DA efflux from live PC12 cell after being stimulated, which has important scientific and practical value for clinical diagnosis and monitoring.

Review—Catalytic Electrochemical Biosensors for Dopamine: Design, Performance, and Healthcare Applications

“…A similar design, consisting of cobalt oxyhyroxide and carbon black nanoflake nanocomposites demonstrated oxidase-like activity and the capability to detect dopamine from cell-secretion with an LOD of 660 nM and linear range from 1-950 μM. 152 Shetty et al measured dopamine secretion from SH-SY5Y neuroblastoma cell lines using a polyoxometalate-ϒ-cyclodextran MOF nanozyme deposited on a laser-scribed graphene electrode. The sensor had an LOD of 10 nM and a linear range of 0.05-1,000 μM DA.…”