Detection of redox potential evolution during the initial stage of an acute wound based on a redox-sensitive SERS-active optical fiber.

To detect redox potential evolution during the initial stage of an acute wound, a redox-sensitive SERS-active optical fiber was fabricated by integrating redox-sensitive SERS probes in a hole of an optical fiber. The redox-sensitive SERS-active optical fibers carried redox-sensitive SERS probes into the inside of a wound to sense its redox potential. The laser was transmitted to the redox-sensitive SERS probes in the body by optical fibers, and the SERS signals of the redox-sensitive SERS probes were transferred out of the body by optical fibers to indicate the redox potentials in the wound. The redox-sensitive SERS probes dynamically sensed the redox potential in vivo, and their SERS signals were collected constantly to indicate the redox potentials. The assessments in vivo and in vitro proved the responsiveness of redox-sensitive SERS-active optical fibers. The redox potential evolution during the initial stage of an acute wound with the treatments of different concentrations of glucose was detected to verify the feasibility of redox-sensitive SERS-active optical fibers to dynamically detect redox potentials in vivo. The redox-sensitive SERS-active optical fiber would be a versatile tool to explore the roles of redox potentials in living organisms.

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.