Simultaneous detection of dopamine and ascorbic acid by using a thread-based microfluidic device and multiple pulse amperometry

Author(s)

dos Santos, Vanessa W. ; Martins, Gustavo ; Gogola, Jeferson L. ; Kalinke, Cristiane ; Agustini, Deonir ; Bergamini, Marcio F. ; Marcolino-Junior, Luiz H.

• Document type: Journal article
• Source: ANALYTICAL METHODS; v. N/A, p. 8-pg., 2023-09-04.

Abstract

This study presents a novel approach for the simultaneous detection of ascorbic acid (AA) and dopamine (DA) using an affordable and user-friendly microfluidic device. Microfluidic devices, when combined with electrochemical detectors like screen-printed electrodes (SPEs), offer numerous advantages such as portability, high sample throughput, and low reagent consumption. In this study, a 3D-printed microfluidic device called a & mu;TED was developed, utilizing textile threads as microfluidic channels and an unmodified SPE as the amperometric detector. The method employed multiple pulse amperometry (MPA) with carefully selected potential values (+0.65 V and -0.10 V). The reduction current signals generated by dopamine o-quinone were used to calculate a correction factor for the oxidation signals of ascorbic acid, enabling simultaneous quantification. The developed microfluidic device ensured a stable flow rate of the carrier solution at 1.19 & mu;L s-1, minimizing the consumption of samples and reagents (injection volume of 2.0 & mu;L). Under the optimized experimental conditions, a linear range from 50 to 900 & mu;mol L-1 was achieved for both DA and AA. The obtained sensitivities were 2.24 & mu;A L mmol-1 for AA and 5.09 & mu;A L mmol-1 for DA, with corresponding limits of detection (LOD) of 2.60 & mu;mol L-1 and 1.54 & mu;mol L-1, respectively. To confirm the effectiveness of the proposed method, it was successfully applied to analyze AA and DA in a commercial blood serum sample spiked at three different concentration levels, with a medium recovery rate of 70%. Furthermore, the MPA technique demonstrated its simplicity by enabling the simultaneous determination of AA and DA without the need for prior separation steps or the use of chemically modified electrodes. This study presents a novel approach for the simultaneous detection of ascorbic acid (AA) and dopamine (DA) using an affordable and user-friendly microfluidic device. (AU)

• FAPESP's process: 19/00473-2 - Development of 3-dimensional (3D) printed electrochemical biosensors with PLA polymer and graphene for the determination of biomolecules and diagnosis of diseases
• Grantee: Cristiane Kalinke
• Support Opportunities: Scholarships in Brazil - Post-Doctoral