Copper Nitroprusside-Based Electrochemical Sensor for Detection of Tryptophan

This work presents a novel electrochemical approach for detecting tryptophan through its interaction with copper nitroprusside,which is synthesized using a simple chemical co-precipitation method.The utilization of the reduction reaction inherent to copper nitroprusside effectively exhibits high selectivity against common interferences present in urine,such as melatonin,lactate,cytosine,cytidine,urea,ascorbic acid,creatine,creatinine,tyrosine,glycine,alanine,arginine,and lysine.The method demonstrates two linear ranges:0.0-0.15 mmol/L and 0.15-2.0 mmol/L with the sensitivities of 119.7±0.2μA/(mmol/L)and 9.9±0.4μA/(mmol/L),respectively.The limit of detection(3S_(B)/m)was determined to be 5.5μmol/L.Application of the sensor in synthetic urine yielded the recovery of 103%±5%.