Bioinspired Micropatterned Superhydrophilic Au-Areoles for Surface-Enhanced Raman Scattering (SERS) Trace Detection

Surface-enhanced Raman scattering (SERS) provides an approach for the label-free and miniaturized detection of the trace amount of analyte molecules. A SERS microchip of Au-areoles array, mimicking the areole on the cactus, is facilely and controllably prepared through selectively electrochemical deposition on patterned superhydrophilic–superhydrophobic substrates. The Au-areoles are full of SERS hot spots thanks to the large amounts of sharp edges, tips, and coupled branches. Meanwhile, the superhydrophilic sites on the superhydrophobic substrate can collect the target molecules into those hot spots. The combination of the SERS enhancement of the nanostructured-Au and the collective effect of the superhydrophilic–superhydrophobic pattern endows the microchip with sample-effective, ultrasensitive, and efficient Raman detection capabilities, which are demonstrated by integrated detection of femtomol Rhodamine 6G and diverse bioanalytes. The chip can also be used for mutually independent multisample detection without interference.