Rapid and universal detection of ovalbumin based on N,O,P-co-doped carbon dots-fluorescence resonance energy transfer technology

Fluorescence resonance energy transfer (FRET), a near-field energy transfer from a fluorescent donor to a fluorescent acceptor within close proximity, has been widely used in biosensing. In this study, a rapid and universal sensor for the detection of ovalbumin (OVA) using nitrogen, oxygen, phosphoric co-doped CDs (NOP-CDs) and graphene oxide (GO) was established based on the FRET technology. First, novel NOP-CDs peak at 443 nm were synthesized by a one-pot hydrothermal method using egg powder and phosphorus acid. Then, in the absence of OVA, the fluorescence of OVA-antibody modified NOP-CDs was quenched by GO via electrostatic attraction and π-π stacking interaction due to the FRET effect. The introduced OVA competed to displace the GO by special binding with the anti-OVA, resulting in the recovery of the fluorescence. This sensor displayed a linear response to OVA from 0.5 to 15 μg/mL with a detection limit of 153 ng/mL and was successfully applied to the detection of the OVA sample with recoveries ranging from 99.25 to 118.90%. In summary, the green and easy-to-synthesize nano-material was used in this method, the accurate detection results, and the simple process exhibited the great potential of this method for practical applications.