All-in-One Preparation Strategy Integrated in a Miniaturized Device for Fast Analyses of Biomarkers in Biofluids by Surface Enhanced Raman Scattering

Complex and tedious sample preparation processes have greatly limited rapid analyses of biological samples. In this work, an all-in-one sample preparation strategy based on a miniaturized gas membrane separation/oven ring enrichment (GMS/ORE) device was developed for efficient surface enhanced Raman scattering (SERS) analyses of trace biomarkers in biofluid samples. This strategy integrating gasification separation, liquid trapping, derivatization SERS activation, and coffee-ring enrichment could highly promote the efficiency of sample preparation. Meanwhile, the edges of membranes modified by the hydrophobic-infusing slippery liquid-induced uniform "coffee-ring" effect could significantly improve the sensitivity and stability for SERS quantification. By adapting proper derivatization approaches to the miniaturized GMS/ORE pretreatment, the matrix effects in samples could be prominently eliminated, and clear SERS responses could be obtained for the selective analyses of target biomarkers. The miniaturized GMS/ORE device was practically applied for SERS analyses of trace biomarkers in biofluids, including hydrogen sulfide in saliva samples, creatinine in serum samples, and sarcosine, creatinine, and dimethyl disulfide in urine samples. Accurate quantification of all biomarkers was achieved with recoveries of 89.5%-120.0%, and the contents found by GMS/ORE-SERS matched well with those found by corresponding chromatographic methods with relative errors from -8.6% to 9.3%. The miniaturized GMS/ORE device with multiple parallel processing units could simultaneously treat eight samples in one run with a total analysis time of 40 min. Such an efficient all-in-one strategy integrated on a miniaturized device possesses great potential for fast on-site/point-of-care detection in analytical science and clinical medicine.