CdTe@SiO2 signal reporters-based fluorescent immunosensor for quantitative detection of prostate specific antigen

Yuting Zhao; Wen Gao; Xiaoxiao Ge; Suiqiong Li; Dan Du; Haipeng Yang

doi:10.1016/j.aca.2019.01.019

CdTe@SiO₂ signal reporters-based fluorescent immunosensor for quantitative detection of prostate specific antigen

Anal Chim Acta. 2019 May 30:1057:44-50. doi: 10.1016/j.aca.2019.01.019. Epub 2019 Jan 18.

Authors

Yuting Zhao¹, Wen Gao², Xiaoxiao Ge³, Suiqiong Li³, Dan Du⁴, Haipeng Yang⁵

Affiliations

¹ College of Materials Science and Engineering, Shenzhen Key Laboratory of Polymer Science and Technology, Shenzhen University, Shenzhen, 18060, China; Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China; School of Mechanical and Materials Engineering, Washington State University, Pullman, WA, 99164, USA.
² College of Materials Science and Engineering, Shenzhen Key Laboratory of Polymer Science and Technology, Shenzhen University, Shenzhen, 18060, China.
³ School of Mechanical and Materials Engineering, Washington State University, Pullman, WA, 99164, USA.
⁴ School of Mechanical and Materials Engineering, Washington State University, Pullman, WA, 99164, USA. Electronic address: annie.du@wsu.edu.
⁵ College of Materials Science and Engineering, Shenzhen Key Laboratory of Polymer Science and Technology, Shenzhen University, Shenzhen, 18060, China. Electronic address: yanghp@szu.edu.cn.

PMID: 30832917
DOI: 10.1016/j.aca.2019.01.019

Abstract

In this paper, an immunosensor using CdTe@SiO₂ core-shell nanoparticles as labels was constructed for highly sensitive detection of prostate-specific antigen (PSA). In this approach, CdTe@SiO₂ core-shell nanoparticles were synthesized using the sol-gel method. The additional Cd ions and sulfur source in SiO₂ shell can greatly enhance the fluorescence intensity of CdTe nanocrystals. The reason is the formation of CdS-like cluster in SiO₂ shell, which reduced the quantum size effect. The obtained CdTe@SiO₂ nanoparticles also exhibited excellent biocompatibility, which was ideal for applying in biomarker detection. Furthermore, PSA capture antibodies functionalized magnetic Fe₃O₄ nanoparticles (Fe₃O₄-Ab₁) were utilized in the proposed immunosensor to capture and enrich the PSA. The captured PSA was then immuno-recognized by CdTe@SiO₂ labeled with PSA detection antibodies (CdTe@SiO_2-Ab₂) by forming the sandwich complex Fe₃O₄-Ab₁/PSA/Ab₂-CdTe@SiO₂. The construction of this immunosensor was confirmed by fluorescence spectroscopy. The proposed immunosensor showed a good linear relationship between the fluorescent intensity and the target PSA concentration ranging from 0.01 to 5 ng/mL, and a detection limit as low as 0.003 ng/mL was achieved. The sensor also exhibited good specificity to PSA. This highly sensitive and specific immunosensor has great potential to be used in other biological detection.

Keywords: Core-shell; Immunosensor; Prostate specific antigen; Quantum dots.

MeSH terms

Cadmium Compounds / chemistry*
Humans
Immunoassay / methods*
Magnetite Nanoparticles / chemistry
Prostate-Specific Antigen / analysis*
Silicon Dioxide / chemistry*
Spectrometry, Fluorescence
Tellurium / chemistry*

Substances

Cadmium Compounds
Magnetite Nanoparticles
Silicon Dioxide
Prostate-Specific Antigen
Tellurium
cadmium telluride