Synthesis and Application of Titanium Carbide (Ti3C2)-Cobalt Sulfide (Co3S4) Nanocomposites in Amino Acid Biosensing

Background The fabrication of titanium carbide (Ti₃C₂)-cobalt sulfide (Co₃S₄)-based biosensors with high sensitivity and selectivity can change the biosensor manufacturing industry completely. Molecular and clinical diagnostics, disease progression monitoring, and drug discovery could utilize these sensors for early biomarker detection. MXene (Ti₃C₂) is a two-dimensional material with exceptional electrical conductivity, hydrophilicity, great thermal stability, large interlayer spacing, and a high surface area. Ti₃C₂'s remarkable characteristics make it well-suited for biomolecule immobilization and target analyte detection. Co₃S₄ is a transition metal chalcogenide that has shown great potential in biosensors. Co₃S₄ nanoparticles (NPs) can potentially enhance Ti₃C₂ electrocatalytic activity, particularly in amino acid detection. L-arginine is a semi-essential amino acid, and the body frequently uses it to support healthy circulation and plays a crucial role in protein synthesis. We fabricated the Ti₃C₂-Co₃S₄ biosensor for L-arginine detection. Aim  This study aims to synthesize and apply Ti₃C₂-Co₃S₄ nanocomposites in amino acid biosensing. Materials and methods The Ti₃C₂ nanosheets were synthesized by the selective removal of an aluminum (Al) layer from the precursor (Ti₃AlC₂) using hydrofluoric acid (HF). The resulting mixture serves as an etchant, especially targeting the Al layers on Ti₃AlC₂ while protecting the desired MXene layers at room temperature. Cobalt nitrate hexahydrate was dissolved in deionized water. Sodium hydroxide was added to the cobalt solution and stirred. Thioacetamide was added to the above solution and stirred (Solution B). A mixture of Solution A and Solution B was stirred for 30 minutes. The mixture is transferred to a hydrothermal reactor and maintained at a temperature of 180°C for 12 hours. Once the reaction completes, we cool the resultant mixture to room temperature and then filter it using the washing technique. The sample underwent a 12-hour drying process at 80°C.  Results  This study investigated the use of a biosensor that employed Ti₃C₂-Co₃S₄ NPs to detect the concentration of L-arginine. The X-ray diffraction (XRD) shows clear and distinct peaks, which means that the synthesized Ti₃C₂-Co₃S₄ nanostructures have a crystalline structure. Scanning electron microscopy (SEM) analysis revealed that the sheetlike structure of synthesized Ti₃C₂-Co₃S₄ nanostructures revealed the crystalline morphology. The results of this study show that the Ti₃C₂-Co₃S₄ NP-based biosensor can be used to detect L-arginine in a sensitive and selective way. Conclusion  This study investigated the synthesis of Ti₃C₂-Co₃S₄ NPs and their ability to detect L-arginine levels and show a distinct correlation between the L-arginine concentration and the fluorescence intensity, demonstrating the biosensor's effectiveness in detecting L-arginine levels.