Smart fluorescence aptasensor using nanofiber functionalized with carbon quantum dot for specific detection of pathogenic bacteria in the wound

We developed for the first time a novel and smart nanofiber (NF) network with the electrospinning method to create an amplified fluorescent biosensing platform for the detection of Staphylococcus aureus (S. aureus) bacteria in wound. The sensing platform is constructed based on surface modification of NFs by carbon quantum dots (CQDs) on the NF membrane surface, leading to large fluorescence signal amplification. CQDs synthesis was done from orto-phenylenediamine (OPD) with yellow emission fluorescence. Incorporation of CQDs leads to the uniform fluorescence of modified NFs. The proposed biosensing platform can also be applied to detect S. aureus bacteria with high sensitivity and selectivity via a specific aptamer. The linear sensing range for different S. aureus concentration from 10 to 108 CFU/mL and the detection limit of 10 CFU/mL was attained. For the first time these scaffolds were designed for the detection of specific pathogenic bacteria in wound using fluorescence signal of NFs, which can be seen by the naked eye under UV lamp. Enhancing in the fluorescence intensity after putting the modified NFs on skin wounds of mice for 2 h showed the successful application of this novel aptasensor.