Detection of thiopurine methyltransferase activity in lysed red blood cells by means of lab-on-a-chip surface enhanced Raman spectroscopy

In this contribution, the great potential of surface enhanced Raman spectoscopy (SERS) in a lab-on-a-chip (LOC) device for the detection of analyte molecules in a complex environment is demonstrated. Using LOC-SERS, the enzyme activity of thiopurine S-methyltransferase (TPMT) is analysed and identified in lysed red blood cells. The conversion of 6-mercaptopurine to 6-methylmercaptopurine catalysed by TPMT is observed as it gives evidence for the enzyme activity. Being able to determine the TPMT activity before starting a treatment using 6-mercaptopurine, an optimized dosage can be applied to each patient and serious toxicity appearing within thiopurine treatment will be prevented. Keywords SERS * Microfluidic lab-on-a-chip * Enzyme activity * Thiopurine methyltransferase * 6-Mercaptopurine