"

Cookies ussage consent

Our site saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing our site without changing the browser settings you grant us permission to store that information on your device.

I agree, do not show this message again.

CdTe quantum dot based pH sensitive probes for ascorbic acid determination

KUI YU YI1,* , JI MIN LI1, ZUN LIAN XU1, XIAN FENG LIU1, JUN JUN BAI1

Affiliation

  1. Department of Forensic Chemistry National Police University of China, Shenyang China 110854

Abstract

TGA modified CdTe qua ntum dots were used as pH sensitive probes for the determination of ascorbic acid in aqueous solutions. The fluorescence of the water-soluble QDs could be irreversibly quenched by H+ and the fluorescence intensity of the water-soluble QDs decreased linearly as the pH decreased in the range of 6.45 8.22. Based on this phenomenon, a simple, rapid and specific method for the quick determination of ascorbic acid was proposed. Under optimum conditions, the relative fluorescence intensity was linearly proportional to the concentration of ascorbic acid between 1.2510-5 and 1.0010-4 mol/L with correlation coefficient of 0.9981. The limit of detection was 3.610-6 mol/L. The relative standard deviation (RSD) was 2.1% for a 3.7510-5 mol/L ascorbic acid. As an application, the proposed method was successfully applied to the analysis of ascorbic acid in medical samples including drug tablets and injection solutions, and the results were consistent with those obtained by oxidation–reduction titration method. In addition, the quenching mechanism was also described. CdTe QDs were found to be a satisfactory pH-sensitive probe that could serve as the potential development of fluorescence sensors..

Keywords

Cd Te quantum dots, pH sensitive, Fluorescence quenching, Ascorbic acid, Determination.

Submitted at: Dec. 12, 2012
Accepted at: March 13, 2014

Citation

KUI YU YI, JI MIN LI, ZUN LIAN XU, XIAN FENG LIU, JUN JUN BAI, CdTe quantum dot based pH sensitive probes for ascorbic acid determination, Journal of Optoelectronics and Advanced Materials Vol. 16, Iss. 3-4, pp. 435-442 (2014)