Parallel Analysis of Two Analytes in Solutions or on Surfaces by Using a Bifunctional Aptamer: Applications for Biosensing and Logic Gate Operations

Abstract

A bifunctional aptamer that includes two aptamer units for cocaine and adenosine 5'-monophosphate (AMP) is blocked by a nucleic acid to form a hybrid structure with two duplex regions. The blocked bifunctional aptamer assembly is used as a functional structure for the simultaneous sensing of cocaine or AMP. The blocked bifunctional aptamer is dissociated by either of the two analytes, and the readout of the separation of the sensing structure is accomplished by a colorimetric detection, by a released DNAzyme, or by electronic means that use Faradaic impedance spectroscopy or field-effect transistors. In one configuration, the blocked bifunctional aptamer structure is separated by the substrates cocaine or AMP, and the displaced blocker units act as a horseradish peroxidase-mimicking DNAzyme that permits the colorimetric detection of the analytes. In the second system, the blocked bifunctional aptamer hybrid is associated with a Au electrode. The displacement of the aptamer by any of the substrates alters the interfacial electron transfer resistance at the electrode surface, thus providing an electronic signal for the sensing process. In the third configuration, the blocked aptamer hybrid is linked to the gate of a field-effect transistor device. The separation of the complex by means of any of the analytes, cocaine, or AMP alters the gate potential, and this allows the electronic transduction of the sensing process by following the changes in the gate-to-source potentials. The different systems enable not only the simultaneous detection of the two analytes, but they provide a functional assembly that performs a logic gate "OR" operation.

Highly Sensitive Electrochemiluminescence Assay for Cardiac Troponin I and Adenosine Triphosphate by using Supersandwich Amplification and Bifunctional Aptamer

“…[5][6][7][8] For example, Elbaz et al reported an electrochemical method for the detection of cocaine and adenosine triphosphate (ATP) using a blocked bifunctional nucleic acid. [5] Yan et al developed an electrochemical biosensor for the detection of thrombin and adenosine using two bifunctional aptamers. [6] Nie et al fabricated a bifunctional aptamer-based electrochemical biosensor for the detection of ATP and lysozyme.…”

Control of Noise in Chemical and Biochemical Information Processing

“…Furthermore, the biocatalytic nature of many utilized biomolecular processes, offers certain advantages for analog noise control in the binary-gate circuit design paradigm. [17] Proteins/enzymes [5][6][7][8][9][10][11][12][14][15][16][17][19][20][161][162][163][164][165] and DNA/RNA/DNAzymes [6,7,[166][167][168][169][170][171][172][173][174][175][176][177][178][179][180][181][182] have been extensively used for gates, for realizing small networks and computational units, and for systems motivated [183] by applications.…”

Flow Cytometry-Assisted Detection of Adenosine in Serum with an Immobilized Aptamer Sensor

“…Among the various signal transduction methods, fluorescence has been the most often used due to its high sensitivity and versatility. 5,[20][21][22][23][24][25][26][27] In addition to intensity-based detection, fluorescence wavelength shift, anisotropy, lifetime, and energy transfer have all been reported for designing aptamer-based sensors. 5 Most fluorescent aptamer sensors involve cuvette-based measurements, in which the sensor and target analyte are mixed in a cuvette and the change of fluorescence signal is monitored with a fluorometer.…”