An antioxidation-responsive SERS-active microneedle for detecting the antioxidant capacity in living organisms

To detect the antioxidant capacity in living organisms, an antioxidation-responsive SERS-active microneedle was fabricated by adsorbing resazurin on miniature SERS substrates, SERS-active microneedles. The SERS intensity ratio of characterized peaks of resazurin and its product, resorufin, was adopted and verified as an indicator of antioxidant capacity. The feasibility of detection of the antioxidant capacity in living organisms was proved by using the fabricated SERS-active microneedles to detect the antioxidant capacity of lipopolysaccharide-induce inflammatory animal models. The fabricated SERS-active microneedles can be inserted into target soft tissues with minimal invasion to detect their antioxidant capacity. The fabricated SERS-active microneedles would be a novel tool to bring the detection of antioxidant capacity from samplings ex vivo and cells to complex tissues to promote the researches on redox biology in living organisms.