Supersandwich Cytosensor for Selective and Ultrasensitive Detection of Cancer Cells Using Aptamer-DNA Concatamer-Quantum Dots Probes

Abstract

In this work, a signal amplification supersandwich strategy was developed for highly selective and sensitive detection of cancer cells using aptamer-DNA concatamer-quantum dots (QDs) probes. First of all, electrode materials denoted as MWCNTs@PDA@AuNPs were fabricated by multiwall carbon nanotubes (MWCNTs), gold nanoparticles (AuNPs), and polydopamine (PDA) using a layer-by-layer technique. Then, the prepared bases as matrices were applied to bind concanavalin A (Con A), resulting in high stability, bioactivity, and capability for cell capture. Meanwhile, aptamer-DNA concatamer-QDs were designed via DNA hybridization followed by covalent assembling, which incorporated the specific recognition of the aptamer with the signal amplification of the DNA concatamer and QDs. With aptamer-DNA concatamer-QDs as recognizing probes, the model cancer cells (CCRF-CEM cells) were detected using a MWCNTs@PDA@AuNPs modified electrode with trapped Con A by means of fluorescence and electrochemical methods. The proposed supersandwich cytosensor showed high sensitivity with the detection limit of 50 cells mL(-1). More importantly, it could distinguish cancer cells from normal cells, which indicated the promising applications of our method in clinical diagnosis and treatment of cancers.

Application of functional quantum dot nanoparticles as fluorescence probes in cell labeling and tumor diagnostic imaging

“…Based on the high photochemical stability of resisting photobleaching, the cells and organs labeled by QDs can be observed for a long time ( Figure 3) [36,37], unlike the traditional organic fluorescent dyes, which are prone to fluorescence quenching. This also provides a powerful tool for the study of long-term cellular interactions between biological molecules [38].…”

Aptasensors Based on Stripping Voltammetry

“…It exhibits great clinical value in the early diagnosis and prognosis of leukemia. Zhu and his group developed both electrochemical aptasensor and cytosensor for selective and ultrasensitive detection of cancer cells using aptamer-DNA concatamer quantum dot probes by fabricating an supersandwich structure ( Figure 9) in 2013 [78]. DNA concatamers are linear polymeric structures formed by self-association of short DNA fragments through specific interactions.…”

“…Therefore Ramos cell were separated by magnetic separation procedure and the released Cd 2+ form separated CdS-DNA probes was Procedures for (A) the fabrication of aptamer-DNA-concatamer-QDs probes, (B) MWCNTs@polydopamine(PDA)@AuNPs composites. and (C) a supersandwich aptasensor for cancer cells [78].…”

A repeatable assembling and disassembling electrochemical aptamer cytosensor for ultrasensitive and highly selective detection of human liver cancer cells

“…Recently, there have been some attempts for cancer cell detection using electrochemical detection methods, for example electrochemical impedance spectroscopy (EIS) [7][8][9][10], differential pulse voltammetry (DPV) [11][12][13][14], cyclic voltammetry (CV) [15], stripping voltammetry (SV) [16,17] and electrochemical luminescence (ECL) [18][19]. Compared with the typical methods, electrochemical methods do offer the advantages of acceptable sensitivity, operational simplicity, rapid response and low cost.…”