Quantitative SERS assay on a single chip enabled by electrochemically assisted regeneration: a method for detection of melamine in milk

摘要： Reusability of sensors is relevant when aiming to decrease variation between measurements, cost and time of analysis. We present an electrochemically assisted surface-enhanced Raman spectroscopy (SERS) platform with the capability to reverse the analyte-surface interaction, without damaging the SERS substrate, allowing for efficient sensor reuse. The platform was used in combination with a sample pre-treatment step, when detecting melamine from milk. We found that the electrochemically enhanced analyte-surface interaction results in significant improvement in detection sensitivity, with detection limits (0.01 ppm in PBS and 0.3 ppm in milk) below the maximum limit allowed in food samples. The reversibility of interaction enabled continuous measurement in aqueous solution and a complete quantitative assay on a single SERS substrate.