Ordered plasmonic bowl structures as SALDI-MS platform for sensitive detection of small molecule pollutants in environment and food

The sensitive detection of small molecule pollutants in environment and food is crucial for safeguarding public health and maintaining ecological balance. Although surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) has shown great potential in small molecule analysis, its widespread application is hindered by limited laser desorption/ionization (LDI) efficiency and poor signal repeatability. A key challenge lies in developing substrates that can overcome these limitations. In this study, we address this critical issue by preparing an ordered plasmonic bowl structure as an advanced SALDI-MS substrate. The unique bowl structure significantly enhances localized surface plasmon resonance effects—particularly at the edges, bottoms, and inter-bowl gaps—facilitating the efficient generation and migration of hot electrons, which improves LDI efficiency. Additionally, the large contact area of the bowl structures increases the hotspot density, thereby amplifying analyte signal intensity. This substrate enables the sensitive detection of small molecule pollutants (dye molecules, antibiotics, and pesticides) over a broad concentration range from 1 mM to 100 nM. The ordered plasmonic bowl substrate presents a promising platform for the rapid and sensitive detection of small molecule pollutants in environmental and food samples.