A highly selective and sensitive detection of insulin with chemiluminescence biosensor based on aptamer and oligonucleotide-AuNPs functionalized nanosilica @ graphene oxide aerogel.

A novel, highly selective and sensitive chemiluminescence (CL) biosensor for insulin (INS) detection was proposed based on aptamer and oligonucleotide-gold nanoparticles functionalized nanosilica @ graphene oxide aerogel. Initially, nanosilica functionalized graphene oxide aerogel (SiO2@GOAG) was successfully prepared and the composite showed rich pore distribution, large specific surface area and good biocompatibility. Insulin aptamer (IGA3) was used as a biorecognition element and oligonucleotide functionalized gold nanoparticles (ssDNA-AuNPs) was used as CL signal amplification materials, which were functionalized on the surface of SiO2@GOAG. The multi-functionalized composite - ssDNA-AuNPs/IGA3/SiO2@ GOAG was obtained and used to construct the CL biosensor for insulin detection. When insulin is present in a sample, the insulin will bind to the IGA3, which will result in the release of ssDNA-AuNPs. The released ssDNA-AuNPs would catalyze the luminescence of luminol and H2O2. The linear range of the CL biosensor for insulin detection was 7.5 × 10-12 to 5.0 × 10-9 moL/L and the detection limit was 1.6 × 10-12 moL/L (S/N = 3). The selectivity and stability of the CL biosensor were also studied and the results showed that the biosensor exhibited high selectivity and good stability due to the introduction of ssDNA-AuNPs/IGA3/SiO2@GOAG. The CL biosensor was finally used for recombinant human insulin detection in recombinant human insulin injection and the results were satisfactory.