Dopamine-mediated Copper Nanoclusters Applied For Detecting Tetracyclines And Establishing The Fluorescent Sensor Of Carbon Dots Derived From Tomato Juice

The present work mainly focuses on fluorescent probe,using fluorescent metal nanoclusters and fluorescent carbon dots as the foundation of the fluorescent probes signal.We concentrate on the design and synthesis of two fluorescent materials:a kind of copper nanoclusters templated with dopamine and a kind of carbon dots derived from tomato juice.The spectral characteristics,structures,chemical stability of the fluorescent materials were investigated.We build up an analytical strategy for the detection of tetracyclines selectively and facilitating their applications in real simple.In addition,we used carbon dots for biological imaging.The main works are summarized as follows:?1?Herein,synthesizing Cu nanoclusters?Cu NCs?templated with dopamine has been first successfully established by reducing Cu SO₄ in aqueous medium with Na BH₄ and N₂H₄·H₂O,and this type of nanoclusters emitted cyan high-fluorescence.Subsequently,the as-prepared Cu NCs were investigated by UV-vis absorption,fluorescence spectroscopy and HR-TEM.The best fluorescence excitation and emission of the Cu NCs are at 425 nm and 485nm,and emitted obvious cyan fluorescence.The diameter of the Cu NCs is 2-3 nm,and there is no agglomeration.In addition,the Cu NCs described here was applied for detection of tetracyclines?TCs?,which was based on forming new bonds between the surfaces of Cu NCs and TC,so that leading to the fluorescence quenching.So we use the proposed analytical detection limit of 9.2×10^-7 mol·L^-1.Then the chlortetracycline and doxycycline were tested separately,but the sensitivity is low and the detection range is narrow.Significantly,the method is applied to the analysis of TC in milk,which further confirms the practicability.Meaningfully,the Cu NCs described here were further applied for fluorescent painting and coding.?2?Synthesizing carbon dots?CDs?with an innovative and green strategy using tomato juice as carbon source.On the one hand,the carbon source material used is green,on the other hand the synthesized CDs has the advantages of good light bleaching,high fluorescence quantum yield,good stability and low toxicity.HR-TEM results shows that the average particle size is 3 nm,and it is evenly distributed.The result of FTIR shows that the surface of CDs contains functional groups such as-OH,-NH and-COOH.Then we used the synthesized carbon dots for biologic imaging.The above results have an important value for us to understand the performance of CDs and to apply them to sensing analysis.