Han Mingyu, Hlaing Mya Myintzu, Stoddart Paul R, Greene George W
Commonwealth Scientific and Industrial Research Organization (CSIRO), Agriculture and Food, 671 Sneydes Road, Werribee, VIC 3030, Australia.
School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Hawthorn, VIC 3122, Australia.
Biosensors (Basel). 2024 Dec 3;14(12):591. doi: 10.3390/bios14120591.
Surface-enhanced Raman scattering (SERS) is a powerful optical sensing platform that amplifies the target signals by Raman scattering. Despite SERS enabling a meager detection limit, even at the single-molecule level, SERS also tends to equally enhance unwanted molecules due to the non-specific binding of noise molecules in clinical samples, which complicates its use in complex samples such as bodily fluids, environmental water, or food matrices. To address this, we developed a novel non-fouling biomimetic SERS sensor by self-assembling an anti-adhesive, anti-fouling, and size-selective Lubricin (LUB) coating on gold nanoparticle (AuNP) functionalized glass slide surfaces via a simple drop-casting method. Compared to a conventional AuNPs-SERS substrate, the biomimetic SERS meets the requirements of simple preparation and enables direct droplet detection without any sample pre-treatment. Atomic force microscopy was used to confirm the self-assembled Lubricin coating on the AuNP surface, acting as an anti-fouling and size-selective protection layer. A series of Raman spectra were collected using melamine as the target analyte, which was spiked into 150 mM NaCl solution or undiluted milk. It was demonstrated that the LUB coating effectively prevents the detrimental fouling generated by the proteins and fats in milk, ensuring the clear detection of melamine. Our sensor showed high selectivity and could detect melamine in milk at concentrations as low as 1 ppm. Given that the EU/US legal limit for melamine in food is 2.5 ppm, this sensor offers a promising, cost-effective solution for routine screening and has potential applications for detecting food adulteration in the food safety, environmental monitoring, aquaculture, and biomedical fields.
表面增强拉曼散射（SERS）是一种强大的光学传感平台，它通过拉曼散射放大目标信号。尽管SERS能够实现极低的检测限，甚至在单分子水平上也是如此，但由于临床样本中噪声分子的非特异性结合，SERS也倾向于同等程度地增强不需要的分子，这使得它在诸如体液、环境水或食品基质等复杂样本中的应用变得复杂。为了解决这个问题，我们通过一种简单的滴铸方法，在金纳米颗粒（AuNP）功能化的玻璃载玻片表面自组装了一种抗粘附、抗污染和尺寸选择性的润滑素（LUB）涂层，开发了一种新型的防污仿生SERS传感器。与传统的AuNPs-SERS基底相比，这种仿生SERS满足了制备简单的要求，并且无需任何样品预处理就能直接进行液滴检测。原子力显微镜用于确认AuNP表面自组装的润滑素涂层，其作为一种防污和尺寸选择性的保护层。使用三聚氰胺作为目标分析物收集了一系列拉曼光谱，三聚氰胺被添加到150 mM NaCl溶液或未稀释的牛奶中。结果表明，LUB涂层有效地防止了牛奶中蛋白质和脂肪产生的有害污染，确保了三聚氰胺的清晰检测。我们的传感器显示出高选择性，能够检测低至1 ppm浓度的牛奶中的三聚氰胺。鉴于欧盟/美国食品中三聚氰胺的法定限量为2.5 ppm，这种传感器为常规筛查提供了一种有前景的、具有成本效益的解决方案，并且在食品安全、环境监测、水产养殖和生物医学领域检测食品掺假方面具有潜在应用。
