Rapid acrylamide detection in drinking water using surface-enhanced raman spectroscopy

Overview

This solution offers a rapid, reliable, and quantitative method for detecting acrylamide in drinking water using surface-enhanced Raman spectroscopy (SERS). Conventional acrylamide detection relies on chromatography and mass spectrometry, which are expensive, time-consuming, and require stringent quality control. The proposed SERS-based approach addresses these limitations by delivering results in approximately one minute at a cost of less than $2 per analysis, while using environmentally friendly chemicals. This makes it well suited for routine water quality monitoring, regulatory compliance testing, and industrial process control where speed and affordability are critical.

Technical specifications

The technology is built on silver nanowire (AgNW) substrates fabricated through a polyol synthesis process, which is cost-effective, scalable, and straightforward. Poly(vinylpyrrolidone) (PVP), an environmentally friendly stabilizing agent, coats the nanowires and contributes to high colloidal stability. Flexible, free-standing AgNW foils are produced by vacuum filtration, then treated with NaBH4 and hot water to reduce the PVP layer thickness. The foils are cut into 0.5 mm × 0.5 mm pieces, and 20 μL of acrylamide solution is drop-cast onto each substrate for analysis.

Detection relies on both electromagnetic and chemical enhancement mechanisms in the near field of the metal nanostructures. The hydrogen bonding interaction between PVP and acrylamide improves analyte adsorption, amplifying the SERS signal. Characteristic acrylamide bands at 1291 cm⁻¹, 1631 cm⁻¹, 2979 cm⁻¹, 3013 cm⁻¹, and 3095 cm⁻¹ have been identified. Preliminary experiments have achieved a limit of detection of 100 mg/L, with ongoing work targeting a detection limit of 0.5 μg/L by optimizing PVP thickness (reducing from 3 nm to 1 nm) and exploring alternative substrates including gold nanostars with quantum dots, laser-induced periodic surface structures, and photochemically etched silicon surfaces. LC/MS-MS will be used for confirmatory measurements during development.

Technology readiness level

The technology is currently at an early-to-mid stage of development. Silver nanowire synthesis, foil fabrication, and initial SERS measurements have been completed, with characteristic acrylamide bands successfully detected. The current limit of detection stands at 100 mg/L, and optimization efforts are underway to reach the target sensitivity of 0.5 μg/L. Future validation will include refining PVP thickness, evaluating additional nanostructured substrates, and confirming results with LC/MS-MS. The method is not yet commercially ready but shows strong potential for further development toward a practical, deployable water quality monitoring tool.