Desenvolvimento de metodologia analitica para determinação de dopamina usando dispositivo microfluidico analitico baseado em papel (μPAD)

Abstract

Dopamine is a neurotransmitter which is used as an indicator of diseases such as Parkinson's disease and schizophrenia, being its determination and quantification necessary to carry out early diagnosis. Common methods for dopamine determination, as an example HPLC coupled to Uv-visible spectroscopy, are analyzes of high cost. The present work describes the development of a colorimetric method for the determination of dopamine by means of an analytical microdevice based on paper (μPADs) aiming a low-cost analysis. The method is based on a 1:1 mole ratio oxidation reaction where dopamine reduces Fe3+ (which shows a yellow color) to Fe2 +, which is capable of complex with phenanthroline yielding an orange complex that shows a signal in the visible spectrum by around 510 nm. The PAD devices were manufactured by wax printing and changes in color intensity were recorded using a cell phone with a macro-coupled lens. This method allowed a LD = 0.49 μM and an LQ = 1.6 μM with R = 0.89837. A Uv-Visible spectroscopic study also allowed to calculate a LD = 1.30μM and LQ = 4.32μM with R = 0.9913 for DA.