Electrochemical And Optical Sensors Based On Copolymer Composites And Upconverting Nanorods

Carrier-based chemical sensors are conventional analysis methods with well-established theory and routine.However,there are still some drawbacks of electrodes and optodes.For electrodes,plasticizer leaching may induce a serious inflammatory response and decrease sensor lifetime.For optodes,it's essential to minimize the influence of background absorption and autofluorescence in biological samples.In order to improve sensor properties,works have been done as follows:(1)We fabricated Ag+-selective-electrodes with different ratios MMA-DMA copolymers,which synthetized via free radical polymerization and atom-transfer radical polymerization.MMA-DMA copolymer is a new type polymer and DMA acts as internal plasticizer,which avoids the plasticizer leaching and provides the possibility of their use in biological fields.The physical properties of different ratios of the copolymers have been researched.From the response curves,we can get the slopes and the detection limits.Compared all the data,the best limit of detection was found when the ration of MMA-DMA of 42-58 was utilized.(2)We reported here a lead ion selective optode incorporating NaYF4:Er,Yb upconverting nanorods,chromoionophore ETH 5418 and lead ionophore together in hydrophobic polymer matrixes.The absorption spectra of protonated and unprotonated ETH 5418 overlap the two emission peaks of the upconverting material,respectively,which allows the fluorescent ion sensing based on the inner filter effect.The proposed optodes exhibited highly selective and reproducible sensing property for measuring lead ions in the range of 10-6 M to 10-2 M at pH 5.Because the excitation source is 980 nm and the emission wavelength lies in the near-infrared region,the sensors have been successfully used in complex samples for example plasma with minimized background absorption and sample autofluorescence.The lead levels of artificial industry wastewater samples obtained by the optode were comparable with the known addition amounts of Pb(NO3)2,providing a new method for testing Pb2+ in the industry wastewater.