Turn-on electrochemiluminescence sensing of melatonin based on graphitic carbon nitride nanosheets

Abstract

• A sensitive turn-on ECL sensor was designed for detection of melatonin. • Graphitic carbon nitride nano-sheets (g-C3N4 NSs) were used as an ECL probe. • The developed ECL sensor exhibited low detection limit of 6.2 × 10-15 M. • The ECL sensor was successfully applied to detect melatonin in human saliva samples. In this work, a turn-on electrochemiluminescence (ECL) sensor for sensitive quantification of melatonin based on graphite carbon nitride (g-C 3 N 4 ) was prepared on the surface of a glassy carbon electrode (GCE). In this ECL sensor, graphitic carbon nitride nano-sheets (g-C 3 N 4 NSs) were used as an ECL probe. The ECL intensity of the sensor was gradually increased with the addition of melatonin concentration. The possible mechanism for enhanced ECL signal of g-C 3 N 4 by melatonin is investigated and discussed in detail. Under optimal conditions, a novel, sensitive and selective ECL sensor has been constructed for the detection of melatonin, with a wide linear response range from 1.0 × 10 -14 to 1.0 × 10 -9 M, and an excellent detection limit of 6.2 × 10 -15 M (6.2 fM). Furthermore, the proposed sensor was successfully applied to detect melatonin in human saliva samples with excellent precision, remarkable selectivity, and long-lasting stability.