Mechanism And Application Of Nanocomposite Of Titanium Dioxide Nanotubes Enhanced Electrochemical Luminescence

Due to its remarkable advantages including high sensitivity,simplicity,fast response,controllability,low background noise and wide dynamic range,electrochemiluminescence?ECL?has been regarded as a powerful and promising analytical technique in recent years.Currently,it has been widely applied in environmental monitoring,food safety,immunoassay,medical and clinical diagnosis etc.This paper summarized and discussed the basic principles of ECL analytical methods,common ECL systems and related nano semiconductor materials?mainly nanoscaled TiO₂ and Au/TiNTs nano-composites?.At the same time,in order to further promote the applications of our biosensors used in clinical monitoring,this paper introduced the development status of diabetes in China and foreign countries and the related detection methods for glycosylated hemoglobin?HbA1c?.HbA1c-ECL biosensor,the concrete research contents are as follows:?1?Tatiana nanotubes?TiNTs?had been immobilized onto the indium tin oxide?ITO?coated glass to intensify the electrochemiluminescence?ECL?of luminal and a TiNTs/ITO sensor was successfully developed.The morphology,structure and properties such as specific surface area and transmittance of TiNTs were characterized.In flow injection analyses?FIA?,the results indicated that the TiNTs exhibited very strong electrochemical activity and ECL intensity,thus lowered the requirement on buffer pH and exciting potential.The ECL emission of luminal on functionalized ITO electrode presented sensitive signaling toward hydrogen peroxide,and the ECL sensor showed extraordinarily responses toward the antioxidant.The possible reasons for this phenomenon was discussed,which revealed the mechanism of the intensified ECL of luminol on TiNTs/ITO sensors.Under the optimal conditions,the ECL emission exhibited a linear response within the concentration range from 0.1 mg L ¹ to 30 mg L ¹and an absolute detection limit of 1.65×10^-10 g of resveratrol.The gross antioxidant activities of blueberry and kiwi were determined with satisfactory recoveries.The sensor has a lot of advantages such as higher sensitivity,wider linear range,lower detection limit and a very small sampling volume.More importantly,our technique would be an excellent platform in biological and medical fields for ROSs and AOX studies.?2?The Au/TiNTs nano-composites were successfully synthesized by the physical/chemical action of?3-aminopropyl?trimethoxysilane?APTMS?.The morphology,structure and properties of nano-composites were characterized.An innovative,high performance and glycated hemoglobin?HbA1c?ECL biosensor has been constructed by immobilizing fructosyl amino acid oxidase onto Au nanoparticles?AuNPs?embellished titania nanotubes?TiNTs?functionalized indium tin oxide glass.Under the optimum conditions,fructosyl valine was detected by this ECL biosensor.It exhibited a linear detection range from 4.0×10^-9 mol L^-1 to 7.2×10^-7 mol L^-1 and a limit of detection for 3.8×10^-9 mol L^-1 at the signal-to-noise ratio of 3.The HbA1c levels in whole blood samples of healthy individuals and diabetic patients were evaluated with the designed biosensor after pre-treatment of hydrolysis.The results of our detections were in good accordance with those of a standard method.At the same time,compare with other current testing methods,including electrochemical methods,our ECL biosensor has some advantages including high sensitivity,nimble usage and low cost,which implies its great promising application in point-of-care testing?POCT?for rapid in vitro diagnosis of HbA1c.