Brushite nanoparticles based electrochemical sensor for detection of uric acid, xanthine, hypoxanthine and caffeine

• Published in: Analytical biochemistry Vol. 659; p. 114947
• Main Authors: Sudhan, N., Anitta, S., Meenakshi, S., Sekar, C.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.12.2022
• Subjects: Ascorbic Acid; Brushite; Caffeine; Electrochemical sensors; Electrochemical Techniques; Electrodes; Humans; Hypoxanthine - chemistry; Hypoxanthine - urine; Nanoparticles; Purine derivatives; Simultaneous sensing; Uric Acid - urine; Xanthine - chemistry; Xanthine - urine; Brushite; Purine derivatives; Simultaneous sensing; Electrochemical sensors
• ISSN: 0003-2697; 1096-0309
• DOI: 10.1016/j.ab.2022.114947

The research in the field of biosensors has recently been focused on the design and development of functional electrode materials that can respond to changes in their biochemical environment. Here, we report the synthesis of dicalcium phosphate dihydrate (DCPD), also known as brushite (CaHPO4·2H2O) by soft chemical method and its application for electrochemical sensing of four different analytes. Phase purity, structure, chemical composition and surface morphology of the synthesized nanoparticles have been investigated using powder XRD, FTIR, SEM, XPS and HRTEM methods. Electrochemical sensor was prepared by modifying GCE with brushite and the modified electrodes were successfully used for either independent or simultaneous determination of uric acid, xanthine, hypoxanthine and caffeine in their mixture. The brushite/GCE exhibited four strong well-defined separate peaks corresponding to the oxidation of UA, XN, HXN and CF in phosphate buffer saline (PBS) at pH 7.4. The fabricated electrode showed low detection limits (S/N = 3) of 0.576, 1.0, 0.076 and 1.26 μM for UA, XN, HXN and CF respectively. Practical application of the fabricated electrode has been demonstrated by determining UA, XN, HXN and CF in human urine and coffee samples by direct method. The brushite offers scope for fabrication of sensor systems for implantable medical applications. [Display omitted] •Dicalcium phosphate dihydrate nanoparticles were synthesized by simple chemical precipitation method.•The brushite nanoparticles exhibited an improved catalytic activity towards the oxidation of uric acid, xanthine, hypoxanthine and caffeine.•DCPD modified GC electrodes were successfully used for either independent or simultaneous determination of multi analytes.•Practical application of the fabricated electrode was demonstrated by determining UA, XN, HXN and CF in human blood serum, urine and coffee by a direct method.•Applications of the synthesized brushite nanoparticles have the unique advantages in the implantable investigations.