CdTe amplification nanoplatforms capped with thioglycolic acid for electrochemical aptasensing of ultra-traces of ATP.
A "signal off" voltammetric aptasensor was developed for the sensitive and selective detection of ultra-low levels of adenosine triphosphate (ATP). For this purpose, a new strategy based on the principle of recognition-induced switching of aptamers from DNA/DNA duplex to DNA/target complex was designed using thioglycolic acid (TGA)-capped CdTe quantum dots (QDs) as the signal amplifying nano-platforms. Owing to the small size, high surface-to-volume ratio and good conductivity, quantum dots were immobilized on the electrode surface for signal amplification. In this work, methylene blue (MB) adsorbed to DNA was used as a sensitive redox reporter. The intensity of voltammetric signal of MB was found to decrease linearly upon ATP addition over a concentration range of 0.1nM to 1.6μM with a correlation coefficient of 0.9924. Under optimized conditions, the aptasensor was able to selectively detect ATP with a limit of detection of 45pM at 3σ. The results also demonstrated that the QDs-based amplification strategy could be feasible for ATP assay and presented a potential universal method for other small biomolecular aptasensors.
Department of Chemistry, Razi University, P.O. Box 67149-67346, Kermanshah, Iran. Electronic address: mshamsipur@yahoo.com.
Mojtaba
M
Shamsipur
Department of Analytical Chemistry, School of Chemistry, College of Science, University of Tehran, P.O. Box 14174-66191, Tehran, Iran.
Leila
L
Farzin
Research Center for Science and Technology in Medicine,Tehran University of Medical Sciences, P.O. Box 14197-33131, Tehran, Iran.
Mahmoud Amouzadeh
MA
Tabrizi
Analytical Chemistry Research Laboratory, Mobin Shimi Azma Company, P.O. Box 14768-44949, Tehran, Iran.
Maryam
M
Shanehsaz
D000255:Adenosine Triphosphate / Q000032:analysis*; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D019187:Cadmium Compounds / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D008751:Methylene Blue / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D045663:Quantum Dots / Q000737:chemistry / Q000648:ultrastructure; D012995:Solubility; D013056:Spectrophotometry, Ultraviolet; D013691:Tellurium / Q000737:chemistry*; D013864:Thioglycolates / Q000737:chemistry*; D014867:Water / Q000737:chemistry
D052157:Aptamers, Nucleotide; D019187:Cadmium Compounds; D013864:Thioglycolates; D014867:Water; C017487:2-mercaptoacetate; D000255:Adenosine Triphosphate; D013691:Tellurium; C028337:cadmium telluride; D008751:Methylene Blue
Adenosine triphosphate; Aptasensor; Thioglycolic acid capped CdTe QDs, signal off