Tuning of fluorescence in titanium carbide MXene nanosheets with La3+ ion doping for the recognition of creatinine biomarker in biofluids

There is a strong correlation between the concentration of creatinine in human urine and the overall health of the kidneys. Therefore, there has been a persistent need for a rapid, and cost-effective quantitative method to assay creatinine levels in urine. Herein, green fluorescent La³⁺ doped titanium carbide nanosheets (La³⁺-doped Ti₃C₂ NSs) are fabricated via HF etching method by using Ti₃AlC₂ as MAX phase material and La(NO₃)₃ as a doping agent. As synthesized fluorescent La³⁺-doped Ti₃C₂ NSs are stable, showing green fluorescence under UV light. The as-synthesized La³⁺-doped Ti₃C₂ NSs act as a fluorescent sensor for the sensitive recognition of creatinine biomarker. The La³⁺-doped Ti₃C₂ NSs-based fluorescence method showed a fluorescence quenching at emission wavelength 518 nm towards creatinine with a linear range of 0.25–7.5 μM and detection limit of 63.44 nM. The paper strip based on La³⁺-doped Ti₃C₂ NSs was developed for the visual identification of creatinine. Furthermore, La³⁺-doped Ti₃C₂ NSs were used as probes for imaging of Saccharomyces cerevisiae cells. Also, the as-fabricated La³⁺-doped Ti₃C₂ NSs propose a quick response giving a cost-effective analytical strategy for the selective assay of creatinine in biofluids (plasma and urine).