SERS and EC dual-mode detection for dopamine based on WO₃-SnO₂ nanoflake arrays

As an important neurotransmitter, the detection of dopamine (DA) is of great significance for the diagnosis and treatment of neurological diseases. In this study, WO₃-SnO₂ nanoflake arrays were synthesized on fluorine-doped tin oxide (FTO) by hydrothermal synthesis and pulse electrodeposition, revealing significant surface-enhanced Raman scattering (SERS) activity with an enhancement factor (EF) reaching 4.79 × 10⁷. The obvious EF was mainly ascribed to the charge transfer between WO₃-SnO₂ and methylene blue (MB) based on chemical mechanism (CM) and the molecular resonance effect. With the competitive adsorption of DA and absorbed MB, we prepared a SERS and electrochemical (EC) dual-mode detection platform of DA based on the WO₃-SnO₂ nanoflake arrays. The linear range (LR) was 5.00–1.75 × 10³ nmol/L, and the detection limits (LODs) were as low as 1.50 and 0.80 nmol/L by SERS and EC respectively. Besides, the developed detection platform can shield the interference of many neurotransmitters similar to DA, showing good selectivity and excellent stability. In general, the SERS-EC dual-mode detection platform can be well applied to the detection of DA in cell lysate, demonstrating great potential in diagnosis of neurodegenerative diseases.