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Aptamer‐Based Electrochemical Sensor for Label‐Free Recognition and Detection of Cancer Cells
Author(s) -
Pan Chunfeng,
Guo Manli,
Nie Zhou,
Xiao Xilin,
Yao Shouzhuo
Publication year - 2009
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200804563
Subject(s) - aptamer , detection limit , cyclic voltammetry , dielectric spectroscopy , electrode , chemistry , electrochemistry , analytical chemistry (journal) , biosensor , redox , materials science , chromatography , inorganic chemistry , biochemistry , microbiology and biotechnology , biology
An electrochemical biosensor was developed for the label‐free and selective detection of leukemia cells based on aptamer‐modified gold electrode using electrochemical impedance spectroscopy (EIS) technique. The thiol‐terminated aptamer (sgc8c) selected for CCRF‐CEM acute leukemia cells was self‐assembled onto the gold electrode surface as recognition probe, which was characterized by cyclic voltammetry (CV) and EIS using Fe(CN) 6 3−/4− as a redox probe. The surface density of aptamers was determined by chronocoulometric method using a redox cation of Ru(NH 3 ) 6 3+ . Upon incubation of the aptamer‐modified electrode with CCRF‐CEM cells, the electron‐transfer resistance ( R et ) of Fe(CN) 6 3−/4− on the sensor surface increased substantially. Only a small R et change of the sensor to the control negative cell line RAJI was observed, indicating the excellent selectivity of the sensor. The selective capture of CCRF‐CEM cells on the sensor surface was also confirmed by fluorescence microscopy. A linear relationship between R et and the logarithmic value of CCRF‐CEM cells concentration was found in the range of 1×10 4 to 1×10 7 cells/mL, with a detection limit of 6×10 3 cells/mL. This work provided a simple, convenient, low‐cost and label‐free method for early leukemia diagnosis.