Fabrication of a disposable electrode based on recordable gold compact disc modified with Bi-Bi2O2CO3@ graphitic carbon nitride nanocomposite for the simultaneous detection of mesalazine and uric acid in biological fluids

A homemade disposable gold electrode was fabricated from gold compact disc (Au-CDs) and modified Bi2O2CO3@g-C3N4 nanocomposite for the simultaneous detection of mesalazine (5-amino salicylic acid; and uric acid (UA) in aqueous solutions. The Bi-Bi2O2CO3@g-C3N4 nanocomposite was characterized by transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, field emission scanning electron scopy and photoluminescence spectroscopy. The analytical response of the modified g-CDs electrode towards ASA and UA was evaluated by cyclic voltammetry and differential pulse voltammetry. Under optimal conditions, the modified g-CDs electrode was able to detect 5-ASA and UA in the concentration ranges of 1.0-160 and 10-190 mu mol L- 1 with detection limits of 0.65 mu mol L- 1 and 3.07 mu mol L- 1 for 5-ASA and UA, respectively. The prepared Bi-Bi2O2CO3@g-C3N4 nanocomposite exhibited high sensitivity and selectivity towards 5-ASA UA in urine and plasma samples with recoveries in the range of 91.0 %- 109.3 %.