3D Plasmonic Ag Nanodendrites as Highly Efficient SERS Substrates for Ultra-Trace Detection of Ascorbic Acid

A rapid, cost-efficient, single-step metal-assisted growth (MAG) method is employed to synthesize well-defined Ag dendrites on a silicon substrate. The sharply branched dendritic nanostructures support extremely dense 3D plasmonic hotspot networks, offering excellent performance in surface-enhanced Raman scattering (SERS). These substrates are subsequently applied for the label-free, ultrasensitive detection of l-ascorbic acid (vitamin C). In addition to electromagnetic enhancement, the sensing mechanism also relies on charge transfer interactions that modulate characteristic vibrational modes, enabling quantitative analysis. The platform supports a broad detection range (10–9 M to 10–3 M) and a lower detection limit of 7.182 nM of ascorbic acid concentration. Owing to its simplicity, analytical robustness, and high sensitivity, the proposed Ag dendritic SERS system is well-suited for portable diagnostic technologies and real-time biochemical monitoring.