Manganese modified CdTe/CdS quantum dots as an immunoassay biosensor for the detection of Golgi protein-73.
In this paper, a new fluorescence bioassay for Golgi protein-73 (GP73), a promising marker for monitoring liver tumor, was developed by using anti-GP73 antibody (GP73 Ab) capped quantum dots (QDs) coupled with protein A/G agarose beads in an attempt to improve the analysis time, cost and operation. First, carboxylic-functionalized Mn modified CdTe/CdS QDs were synthesized and covalently conjugated with GP73 Ab, then protein A/G agarose beads were specifically combined with the QDs-conjugated Ab to form the QDs-Ab-beads conjugate, which could capture and separate GP73 from the sample through simple centrifugation. It was found that the fluorescence intensity of the above QDs-Ab-beads biosensor could be specifically quenched by GP73 added. A simple, rapid and specific quantitative method for GP73 protein was proposed using the as-prepared QDs-Ab-beads as a biosensor. Under the optimized conditions, the calibration curve of the proposed assay showed good linearity with a correlation coefficient of 0.9935 in the concentration range of 20-150 ng/mL of GP73 protein. The limit of detection (defined as 3σ/K) was 10 ng/mL. The method built exhibited a great potential in the clinic test of GP73.
School of Pharmacy, Nanjing Medical University, Nanjing, Jiangsu 211 166, PR China.
Wei
W
Liu
School of Pharmacy, Nanjing Medical University, Nanjing, Jiangsu 211 166, PR China.
Aixia
A
Zhang
School of Pharmacy, Nanjing Medical University, Nanjing, Jiangsu 211 166, PR China.
Guanhong
G
Xu
School of Pharmacy, Nanjing Medical University, Nanjing, Jiangsu 211 166, PR China.
Fangdi
F
Wei
School of Pharmacy, Nanjing Medical University, Nanjing, Jiangsu 211 166, PR China.
Jing
J
Yang
School of Pharmacy, Nanjing Medical University, Nanjing, Jiangsu 211 166, PR China. Electronic address: huqin@njmu.edu.cn.
Qin
Q
Hu
D015374:Biosensing Techniques / Q000379:methods*; D019187:Cadmium Compounds / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay; D008345:Manganese / Q000737:chemistry*; D008565:Membrane Proteins / Q000032:analysis*; D045663:Quantum Dots / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry*; D013691:Tellurium / Q000737:chemistry*
D019187:Cadmium Compounds; C410824:GOLM1 protein, human; D008565:Membrane Proteins; D013440:Sulfides; C034939:cadmium sulfide; D008345:Manganese; D013691:Tellurium; C028337:cadmium telluride
Fluorescence quenching; Golgi protein-73; Protein A/G agarose beads; Quantum dots