Ultrasensitive detection of enhanced Raman scattering via modified MoS ₂ /TiO ₂ ultrathin nanowire arrays

Uric acid (UA) and creatinine are important metabolic biomarkers closely linked to human health. Reliable detection of these molecules requires analytical methods with high sensitivity and stability. Quantitative analysis of UA by surface-enhanced Raman scattering (SERS) is still difficult because of weak adsorption on substrates and interference from urine components. In this work, we design a hybrid SERS substrate based on titanium dioxide nanowire arrays (TiO 2 -NWAs). The nanowires are coated with an ultrathin molybdenum disulfide (MoS 2 ) layer and further decorated with gold nanoparticles (Au-NPs), forming TiO 2 (NWAs/MoS 2 /Au-NPs). The thin MoS 2 coating preserves the nanowire morphology and builds strong heterojunctions with TiO 2 . These junctions provide abundant adsorption sites and promote charge transfer between the substrate and analytes. The ternary composite shows excellent SERS activity. Its performance arises from the combined effects of localized electromagnetic enhancement and efficient charge transfer. Using this system, UA and creatinine can be detected at very low concentrations, with limits of 10 −6 M and 10 −7 M, respectively. This study demonstrates the essential role of ultrathin MoS 2 in semiconductor/metal hybrid systems. The findings offer a practical framework for biocompatible SERS substrates and support the translation of SERS technology into point-of-care health monitoring.