A composite film prepared from titanium carbide Ti₃C₂T_x (MXene) and gold nanoparticles for voltammetric determination of uric acid and folic acid

In this study, a solution-processing based galvanic deposition approach is described for in-situ deposition of gold nanoparticles (AuNP) on delaminated titanium Ti₃C₂T_x nanosheets under ultrasonication. The nanocomposite (AuNP@Ti₃C₂T_x) was placed on a glassy carbon electrode (GCE) and then applied to electrochemically with label-free, and simultaneously sense uric acid (UA), and folic acid (FA) at physiological pH. The modified GCE has attractive figures of merit: (i) The working potentials for UA and AA are well separated (+0.35 V and 0.70 V vs. Ag|AgCl); (ii) wide linear responses (from 0.03–1520 μM for UA and from 0.02–3580 μM for FA; (iii) good electrochemical sensitivities for both UA and FA (0.53 and 0.494 μAμM⁻¹.cm⁻², respectively), and (iv) detection limits of 11.5 nM (UA) and 6.20 nM (FA). The electrode exhibited good repeatability (RSD = 4.4%), acceptable reproducibility (RSD = 4.1%), and excellent stability (91.8% over one-month storage). The method was applied to analyze spiked serum samples, and modified GCE is shown appreciable recoveries (97.1–98.8% and 96.8–98.0% for UA, and FA, respectively). [Figure not available: see fulltext.].