An Electrochemical ATP Biosensor with Enzymes Entrapped within a PEDOT Film

Abstract

This paper reports on the electrochemical behavior of an ATP biosensor that utilizes glucose oxidase (GOx) and hexokinase (Hex) immobilized within the electroactive polymer, polyethylenedioxythiophene (PEDOT). This biosensor design detects ATP indirectly at 0.85 V vs. Ag/AgCl based on the oxidation current for enzymatically generated H2O2, and at −0.20 V; a potential at which improved analyte selectivity is achieved. The detection figures of merit at both detection potentials are a response time of 15±1 s, an experimental detection limit of 10.0±0.2 μmol L−1 (S/N=3), and a sensitivity in the range of 100–500 mA M−1cm−2.

Metal Nanoparticle Modified Carbon-Fiber Microelectrodes Enhance Adenosine Triphosphate Surface Interactions with Fast-Scan Cyclic Voltammetry

“…On average, ATP current decreased by 54 ± 1% by the 25th injection ( n = 7, Figure ). ATP detection stability with FSCV has not been measured prior and our result indicates potential electropolymerization of ATP in solution leading to chemical fouling on the surface of the electrode; however, the mechanism of ATP polymerization and how it adsorbs to the carbon surface are unclear. , Conversely, when repeating this experiment at AuNP and PtNP-modified carbon-fiber microelectrodes, we show that ATP detection is more stable on the electrode surface (Figure ). AuNP-modified electrodes are more stable than PtNP-modified electrodes with only 13 ± 1% loss ( n = 5) compared to 29 ± 2.2% ( n = 8) at PtNP-modified.…”

“…Rapid decay of the signal over time indicates native metabolism and uptake of ATP within the lymph node slice. 8). This demonstrates the utility of these electrodes for multiplexed detection in the lymph node in the future.…”

“… 1 − 4 The ability to monitor ATP signaling on rapid time scales is important for elucidating the mechanism of action and quantitating the availability of ATP to interact at nearby receptors and transporters during both health and disease. Many methods have been developed to detect ATP including electrochemical aptamer-based sensors, enzyme sensors and surface-modified electrodes, 5 − 8 and fluorescence; 9 , 10 however, many of these methods suffer from slow temporal resolution or the inability to quantitate rapid concentration changes over time. Fast-scan cyclic voltammetry (FSCV) at carbon-fiber microelectrodes is an electroanalytical technique which enables millisecond sensing of electroactive neurochemicals; however, direct electrochemical detection of ATP is difficult due to limited interactions at carbon-fiber surfaces.…”

“…Adenosine-5′-triphosphate (ATP) is an important purine extracellular signaling molecule and has an essential role in a variety of neurological and immunological disorders. − The ability to monitor ATP signaling on rapid time scales is important for elucidating the mechanism of action and quantitating the availability of ATP to interact at nearby receptors and transporters during both health and disease. Many methods have been developed to detect ATP including electrochemical aptamer-based sensors, enzyme sensors and surface-modified electrodes, − and fluorescence; , however, many of these methods suffer from slow temporal resolution or the inability to quantitate rapid concentration changes over time. Fast-scan cyclic voltammetry (FSCV) at carbon-fiber microelectrodes is an electroanalytical technique which enables millisecond sensing of electroactive neurochemicals; however, direct electrochemical detection of ATP is difficult due to limited interactions at carbon-fiber surfaces. , Recently, our lab developed a method to functionalize the surface of carbon-fiber with amines to enable significant improvements in direct ATP detection as facilitated by an increase in electrostatic interactions at the surface .…”

In Vitro Monitoring of Nitric Oxide Release in the Mouse Colon Using a Boron-Doped Diamond Microelectrode Modified with Platinum Nanoparticles and Nafion

“…It is possible that the change in baseline observed is due to a local ionic concentration change at the electrode− solution interface. It is our goal to apply NO and ATP biosensors, which have been prepared and described elsewhere 58 to determine whether nitrergic neurons also store and release ATP along with NO.…”