A supramolecular semiconducting nickel(ii)-metallohydrogel with dual antimicrobial and micro-electronic device applications

Abstract

A multifunctional Ni(II)-based metallohydrogel (NiC-GT) was developed by reacting nickel(II) chloride with guanylthiourea in water under ambient conditions. The resulting hydrogel exhibited excellent mechanical stability, as validated by comprehensive rheological and thixotropic analyses. Field emission scanning electron microscopy (FESEM) revealed a well-organized hierarchical microstructure, while energy-dispersive X-ray (EDX) mapping confirmed the uniform distribution of key elements such as C, N, O, S, Cl, and Ni within the gel matrix. Fourier-transform infrared (FT-IR) spectroscopy provided insights into the non-covalent interactions driving gelation, and powder X-ray diffraction (PXRD) analysis demonstrated the semi-crystalline characteristics of the material. Optical absorption studies indicated the semiconducting behaviour of the hydrogel, with enhanced electron mobility surpassing that of comparable soft materials. Notably, the hydrogel displayed broad-spectrum antibacterial efficacy against both Gram-positive (Bacillus subtilis, Staphylococcus aureus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacterial strains, suggesting its effectiveness in biomedical contexts. The integration of mechanical robustness, semiconducting functionality, and antimicrobial activity positions this Ni(II)-metallohydrogel as a promising candidate for emerging applications in flexible electronic devices, biosensors, and therapeutic systems. This work highlights the synergistic potential of transition metal-coordinated supramolecular systems for advancing smart soft material platforms.