Dual-signal model array sensor based on GQDs/AuNPs system for sensitive protein discrimination

The accurate differentiation and identification of proteins play a vital role in many areas. Herein a novel array sensor is developed for sensitive discrimination of proteins, based on the various optical responses of GQDs/AuNPs system towards different protein species. The simultaneously generated distinct variations of fluorescence and absorbance of GQDs/AuNPs system resulted from the interactions between protein species and sensing units contribute to a dual-signal strategy for protein discrimination. The protein concentration for complete discrimination is low down to 50 nM, and accurate discriminations of protein mixture of different concentrations/molar ratio are achieved. The complementary fluorescence and absorbance response makes this dual-signal model array sensor practicable to sample of complicated matrices, demonstrated by the accurate discrimination of protein species in human urine. Moreover, six strains of microorganisms originated from three different species are also successfully discriminated with 100% accuracy (OD600 = 1.0). (C) 2017 Elsevier B.V. All rights reserved.