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.
['Song|Yu|Y|', 'Li|Yang|Y|', 'Liu|Ziping|Z|', 'Liu|Linlin|L|', 'Wang|Xinyan|X|', 'Su|Xingguang|X|', 'Ma|Qiang|Q|']
D015374:Biosensing Techniques D019187:Cadmium Compounds D048271:Chitosan D005453:Fluorescence D006801:Humans D057230:Limit of Detection D009113:Muramidase D045663:Quantum Dots D013050:Spectrometry, Fluorescence D013691:Tellurium D015032:Zinc
Nanosensor Lysozyme Quantum dots Fluorescence turn on–off