Objective Carbon dots (CDs) are an emerging carbon nano-material which is environmentally-friendly, economical , efficient and stable .Their fluorescence properties can match the semiconductor quantum dot .Moreover , CDs have more excellent biocompatibilities .The purpose of this experiment is to apply CDs to the fluorescent immune probe to make them a new label , which can replace the traditional fluorescent dyes .Methods Using microwave heating method , the high strength fluorescent carbon dots were prepared .Wtih the EDC coupling method , the high strength fluorescent car-bon dots could bond with Escherichia coli antibodies to form a complex immune fluorescent probe .Specific recognition exper-iments were carried out in the model of E.coli O157∶H7.Results CDs were successfully applied to immune recognition of E.coli O157∶H7 and multicolor fluorescence was observed .Conclusion CDs can serve as a label of the fluorescent im-mune probe , and are expected to become a new type of low toxicity biosensor with independent intellectual property rights .

Objective To fabricate an immunofluorescence probe system of carbon dots conjugated antibody based on antigen-antibody reaction principles.Methods A green one-step microwave assisted pyrolysis method was applied to preparing fluorescent carbon dots (CDs) using aminoglucose as carbon source and the obtained CDs were conjugated with antibody via EDC/NHS reactions to build CDs based fluorescent probe.Furthermore,the properties of CDs and CDs based probe system were evaluated by Fourier transform infrared (FTIR) spectra,transmission electron microscopy (TEM),UV-vis absorption and so on.Results The as-prepared CDs showed excellent fluorescence and hydrophilicity and CDs based immunofluorescence probe exhibited the capability of quick detection of E.coli O157:H7.Cinclusion Fluorescent CDs as one new emerging environment-friendly nanomaterial has great potential in biosensors.