Carbon dots based photoelectrochemical sensors for ultrasensitive detection of glutathione and its applications in probing of myocardial infarction

- Carbon dots (CDs) based photoelectrochemical (PEC) sensors for ultrasensitive GSH detection were developed.
- CDs showed both photoelectric and catalytic properties toward GSH in our designed PEC sensors.
- Three different nanomaterials (AgNPs, GO and MS) were introduced into CDs to enhance the PEC sensing properties for GSH.
- CDs@MS based PEC sensors exhibited best LOD (6.2 nM) and good selectivity toward GSH detection.
- The probing of MI conditions was achieved by detection of GSH from myocardia cells.

In this work, photoelectrochemical (PEC) sensors based on carbon dots (CDs) were developed for ultrasensitive detection of glutathione (GSH) without additional catalysts. In this PEC sensing system, CDs exhibited both photoelectric and catalytic properties. Silver nanoparticles (AgNPs), graphene oxide (GO), and mesoporous silica (MS) were introduced in order to enhance the sensing properties of CDs for GSH. Among the different hybrid nanocomposites, CDs@MS based PEC sensors exhibited the best sensing properties: the sensitivity and limit of detection (LOD) for GSH were found to be 57.6 nA μM− 1 and 6.2 nM (S/N = 3), respectively, in the linear range 0.02-4 μM. In addition, the developed PEC sensors showed a high selectivity for GSH even with interferences of other biological thiols and amino acids. The PEC sensor was successfully applied for GSH detection in human serum and probing of myocardial infarction (MI) conditions by estimating the amount of GSH in the myocardial cells of mice, which had been treated with different ischemia/ischemia-reperfusion times. These results indicated that the CDs based hybrid nanocomposites are promising candidates for the development of PEC biosensors with enhanced sensing performances.