Amine-silane-induced Ag–Cu dendrites on Al/ZnO: an integrated SERS monitoring and photodegradation platform for triphenylmethane dyes

Abstract

The trace-level presence and complex matrices of carcinogenic triphenylmethane (TPM) dyes pose significant challenges for their environmental management. Herein, leveraging 3-aminopropyltriethoxysilane (APTES) as a bifunctional inducer, we designed a novel Al/ZnOA/Ag–Cu substrate (A = APTES modification) for simultaneous ultra-trace detection and solar-driven photocatalytic degradation of triphenylmethane (TPM) dyes. The APTES critically orchestrates the growth of bimetallic Ag–Cu dendrites while covalently bridging the support and metals to facilitate charge transfer. The resulting substrate exhibits exceptional surface-enhanced Raman scattering (SERS) activity, achieving an ultra-low detection limit of 9.83 × 10⁻¹⁸ mol L⁻¹ for brilliant green (a model TPM dye) with a high enhancement factor of 4.08 × 10⁷. Electromagnetic simulations confirm the generation of abundant “hot spots” within the dendritic nanogaps. Crucially, the substrate exhibits superior self-regenerating capability, efficiently photodegrading adsorbed dye molecules under simulated sunlight via component synergy. This allows stable SERS performance over at least six detection–regeneration cycles. This study offers a new strategy for constructing hierarchical metallic nanocomposites and provides an advanced integrated platform that combines real-time monitoring with in situ remediation for water purification.