High-throughput label-free detection of Ochratoxin A in wine using supported liquid membrane extraction and Ag-capped silicon nanopillar SERS substrates

Mycotoxins are toxic secondary metabolites produced by fungi, found in a variety of food sources and cause diseases and death in both humans and animals. On-site and easy to use detection would be significant improvement considering the currently used methods. We present an approach, based on surface-enhanced Raman spectroscopy (SERS), where label-free detection of Ochratoxin A (OTA) was achieved in a multiwell SERS detection platform. When quantifying OTA in wine samples the SERS-based detection was used in combination with high throughput supported liquid membrane (SLM) extraction. The obtained detection limit in white wine was 115 ppb and we found that the SERS-based quantification is comparable with LC-MS. However, we also found that the matrix effect from red wine was interfering with both SERS and LC-MS detection. The SLM-SERS method provides a time and cost effective approach for OTA detection, which is a clear advantage over other extraction and direct detection approaches.