Development Of Ultrasensitive Liposome-Quantum Dot Based Optical Nanobiosensor For Detection Of Cancer Cells Without Target Amplification

Nosratollah ZARGHAMI, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Iran
ZAVARI-NEMATABAD A. 3 , ALIZADEH-GHODSI M. 3 , ZARGHAMI F. 3 , PILEHVAR-SOLTANAHMADI Y. 1, 2

1 Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
2 Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
3 Department of Clinical Biochemistry, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran

Purpose: The detection of tumor  cells in early stages is crucial for diagnosis, prevention, and treatment of cancer. In present study, we developed a novel strategy to amplify fluorescence signal for highly sensitive optical detection of cancer cells regarding telomerase activity using liposomes encapsulated with Cadmium Telluride (CdTe) quantum dots (QDs).
Methods:In this strategy, the telomerase extracted from HeLa cells, elangated the biotinylated telomerase substrate (TS) probe; then, the probe was immobilized on streptavidine coated microplate wells. Next, hybridization of immobilized TS probe with biotinilated capture probe was carried out. Aftre that, biotinilated liposomes were attached to capture probe through streptavidin. In final step, liposomes were disrupted by Triton X-100 and the fluorescence activity of released QDs was measured.
Results:The results showed that proposed nanobiosensor could be applied to determine telomerase activity from equivalent down to 10 HeLa cells without the polymerase chain reaction (PCR) amplification of telomerase extension products.
Conclusions:Offered methodis not only convenient and sensitive,but also has a simple operating protocol and wide dynamic range.The platform, might be further applied for the detection of viral reverse transcriptase enzymes and various biological targets with a combination of different probes and aptamers.
Funding source: Funded by Tabriz University of Medical Sciences