A novel ultrasensitive carboxymethyl chitosan-quantum dot-based fluorescence "turn on-off" nanosensor for lysozyme detection.
In this work, we developed an ultrasensitive "turn on-off" fluorescence nanosensor for lysozyme (Lyz) detection. The novel nanosensor was constructed with the carboxymethyl chitosan modified CdTe quantum dots (CMCS-QDs). Firstly, the CMCS-QDs were fabricated via the electrostatic interaction between amino groups in CMCS polymeric chains and carboxyl groups on the surface of QDs. In the fluorescence "turn-on" step, the strong binding ability between Zn(2+) and CMCS on the surface of QDs can enhance the photoluminescence intensity (PL) of QDs. In the following fluorescence "turn-off" step, the N-acetyl-glucosamine (NAG) section along the CMCS chains was hydrolyzed by Lyz. As a result, Zn(2+) was released from the surface of QDs, and the Lyz-QDs complexes were formed to quench the QDs PL. Under the optimal conditions, there was a good linear relationship between the PL of QDs and the Lyz concentration (0.1-1.2 ng/mL) with the detection limit of 0.031 ng/mL. The developed method was ultrasensitive, highly selective and fast. It has been successfully employed in the detection of Lyz in the serum with satisfactory results.
Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun 130012, China.
Yu
Y
Song
Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun 130012, China.
Yang
Y
Li
Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun 130012, China.
Ziping
Z
Liu
Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun 130012, China.
Linlin
L
Liu
Changchun Institute of Applied Chemistry Chinese Academy of Sciences, Changchun 230022, China.
Xinyan
X
Wang
Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun 130012, China.
Xingguang
X
Su
Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun 130012, China. Electronic address: Qma@jlu.edu.cn.
Qiang
Q
Ma
D015374:Biosensing Techniques / Q000379:methods*; D019187:Cadmium Compounds / Q000737:chemistry*; D048271:Chitosan / Q000031:analogs & derivatives* / Q000737:chemistry; D005453:Fluorescence; D006801:Humans; D057230:Limit of Detection; D009113:Muramidase / Q000032:analysis / Q000097:blood*; D045663:Quantum Dots / Q000737:chemistry* / Q000648:ultrastructure; D013050:Spectrometry, Fluorescence / Q000379:methods; D013691:Tellurium / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry
D019187:Cadmium Compounds; C514968:carboxymethyl-chitosan; D048271:Chitosan; D009113:Muramidase; D015032:Zinc; D013691:Tellurium; C028337:cadmium telluride
Fluorescence turn on–off; Lysozyme; Nanosensor; Quantum dots