Combined Detection Of Heavy Metal And Antibiotics Based On Fluorescent Nanotechnology

Heavy metals and antibiotics are two common co-existed pollutants in the environment.However,there are few methods for simultaneous detection of heavy metals and antibiotics in the environment.And the reported methods mainly rely on large-scale instruments,lacking a simple,fast,and easy-to-operate method.Therefore,it’s crucial to establish a simple method that can be used for the simultaneous detection of multiple pollutants in order to cope with the increasing pollution situation.In this study,for the rapid fluorescence detection of fluoroquinolone antibiotics(FQs),a suitable preparation method of graphene carbon quantum dots(GCDs)was developed,which was simple and only required one step of hydrothermal treatment.The obtained GCDs have specific fluorescence response properties to FQs.The working conditions of this kind of GCDs were thoroughly investigated and then successfully applied to the quantitative detection of FQs.When the concentration of FQs was over the range 0-50 μM,the detection limit of FQs was 0.8-2.2 n M.In addition,GCDs with different fluorescence properties could be affected by its average size,which was regulated by the reaction time of the reaction.In order to realize the simultaneous detection of antibiotics and heavy metals,GCDs and cadmium telluride quantum dots(Cd Te QDs)were combined to fabricate a facile fluorescent probe(FFP)by solution gel method.A single excitation/dual emission detection system based on FFP was established for simultaneous detection of FQs and copper [Cu(II)].This system detected FQs by fluorescence enhancement of GCDs and Cu(II)by fluorescence quenching of Cd Te QDs,respectively.If only one FQ coexisted with Cu(II),quantitative analysis could be conducted for them.Taking norfloxacin(NOR)as an example,under optimal conditions,when the concentration of NOR was in the range of 0–50 μM,the fluorescence intensity of GCDs in FFP increased with the concentration of NOR,and the detection limit was 1.6 n M;The fluorescence intensity of Cd Te QDs decreased with the increase of Cu(II)concentration when the concentration ranged from 0 to 10 μM,and the detection limit was 48.4 n M.At the same time,the practical application performance of the system was explored.At different spiked levels,NOR and Cu(II)could be simultaneously detected from four real samples(tap water,drinking water,seawater and milk).The average recoveries of Cu(II)ranged from 85% to 115.1%,and the relative standard deviation was less than1.0%.If there were multiple FQs,the types of FQs could be distinguished by linear discriminant analysis.Using this method in the study,four kinds of FQs were successfully distinguished.Therefore,the single excitation/double emission detection system constructed in this study has the potential to simultaneously detect multiple targets in liquid samples.