Facile synthesis of magnetic ionic liquids/gold nanoparticles/porous silicon composite SERS substrate for ultra-sensitive detection of arsenic

Developing a novel and simple route for the synthesis ultrasensitive and specific SERS substrates is highly desirable and technically important. Here, a magnetic ionic liquid (MIL) assisted strategy is developed, and the high-quality and ultra-sensitive MIL-gold nanoparticles/porous silicon (MIL-Au NPs/PSi) composite substrate were synthesized by a fast and cost effective strategy with the assistance of MIL (1-methyl-3-hexyl imidazole ferric tetrachloride ([C(6)mim]FeCl4). Fundamental SERS performance of this composite substrate was evaluated using rhodamine 6G (R6G). The results showed that MIL make the Au NPs/PSi have great advantages in synergetic enhancement and stability, and the hypersensitive detection of specific substances can be realized by selecting or designing IL. Based on the particularity of MIL ([C(6)mim] FeCl4's function and structure, arsenic was detected with MIL-Au NPs/PSi substrate. The detection limit can reach 0.5 ppb, and the standard curves with regression coefficients of 0.98527 and 0.98965 were established in the linear range of 2-80 ppb and 200-800 ppb. In a word, an advanced method for the preparation of high-performance and designable SERS substrate has been developed, which will certainly show promising applications in detection technology.

Automated summary

A novel approach utilizing magnetic ionic liquid was developed to synthesize high-quality and ultra-sensitive MIL-Au NPs/PSi composite substrates, demonstrating superior catalytic enhancement and stability for detecting specific substances.