A green approach: Eco-friendly synthesis of Gd2Ti2O7/N-GQD nanocomposite and photo-degradation and electrochemical measurement of hydroxychloroquine as a perdurable drug

In this work, gadolinium titanate (GT = Gd2Ti2O7) nanoparticles were synthesized using expired vials of B12 vitamins (reusing the waste) as a capping agent and reductant by a sol–gel technique. Then, GT/N-GQD (nitrogen-doped graphene quantum dots) nanocomposite was prepared by synthesis of N-GQDs in presence of the GT nanoparticles. Next, this nanocomposite was used for photodegradation of hydroxychloroquine sulfate (HCQ) as a multi-function drug with a long half-life during the photocatalytic reactions under visible light. Because of the necessity of measuring the concentration of this drug in human blood serum, tablets, and wastewater, this nanocomposite was utilized as an electrochemical sensor for its detection. Finally, photocatalytic activity of this nanocomposite was approved by 76 % degradation percent of HCQ and the limit of detection (LOD) equals 0.064 nM confirmed that this sensor is the most sensitive sensor prepared for measurement of HCQ, up to now. Since acetaminophen (AC) is one of the most commonly used drugs which is usually consumed along with HCQ, the performance of this sensor was examined in presence of it. The results showed that the presence of AC couldn’t affect the performance of the sensor. The obtained results were supported by a variety of analyses.