Basic Red 9 dye encapsulated graphene oxide-montmorillonite composite: Fluorescent and electrochemical sensor for dopamine in presence of ascorbic acid and uric acid

Abstract

The dye Basic Red 9 has been successfully encapsulated into GO-MMT composite and the probe acts as a “turn on” fluorescence sensor for dopamine (DA) in presence of its main biological counterpart i.e. ascorbic acid (AA), uric acid (UA) along with other biologically important ions and molecules. The limit of detection (LOD) for dopamine detection is found to be 6.57 nM and 5.05 nM in the absence and presence of AA and UA respectively. Glassy carbon electrode modified with the sensor can successfully distinguish between the peaks of DA, AA and UA by cyclic voltammetry technique. The LOD for AA, UA and DA have been calculated as 1.165 nM, 0.875 nM and 3.043 nM respectively. The voltammetric detection of mixture containing DA, AA and UA are free from common interfering ions and species like glucose, cholesterol, Na⁺, K⁺ , Ca²⁺, Fe²⁺.