InGaN/GaN nanowires as a new platform for photoelectrochemical sensors - detection of NADH.
InGaN/GaN nanowire heterostructures are presented as nanophotonic probes for the light-triggered photoelectrochemical detection of NADH. We demonstrate that photogenerated electron-hole pairs give rise to a stable anodic photocurrent whose potential- and pH-dependences exhibit broad applicability. In addition, the simultaneous measurement of the photoluminescence provides an additional tool for the analysis and evaluation of light-triggered reaction processes at the nanostructured interface. InGaN/GaN nanowire ensembles can be excited over a wide wavelength range, which avoids interferences of the photoelectrochemical response by absorption properties of the compounds to be analyzed by adjusting the excitation wavelength. The photocurrent of the nanostructures shows an NADH-dependent magnitude. The anodic current increases with rising analyte concentration in a range from 5µM to 10mM, at a comparatively low potential of 0mV vs. Ag/AgCl. Here, the InGaN/GaN nanowires reach high sensitivities of up to 91µAmM-1cm-2(in the linear range) and provide a good reusability for repetitive NADH detection. These results demonstrate the potential of InGaN/GaN nanowire heterostructures for the defined conversion of this analyte paving the way for the realization of light-switchable sensors for the analyte or biosensors by combination with NADH producing enzymes.
Biosystems Technology, Institute of Applied Life Sciences, Technical University of Applied Sciences Wildau, 15745 Wildau, Germany.
M
M
Riedel
I. Physikalisches Institut, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 16, 35392 Gießen, Germany; Institute of Solid State Physics, University of Bremen, Bremen, Germany.
S
S
Hölzel
I. Physikalisches Institut, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 16, 35392 Gießen, Germany; Institute of Solid State Physics, University of Bremen, Bremen, Germany.
P
P
Hille
I. Physikalisches Institut, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 16, 35392 Gießen, Germany.
J
J
Schörmann
I. Physikalisches Institut, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 16, 35392 Gießen, Germany; Institute of Solid State Physics, University of Bremen, Bremen, Germany.
M
M
Eickhoff
Biosystems Technology, Institute of Applied Life Sciences, Technical University of Applied Sciences Wildau, 15745 Wildau, Germany. Electronic address: flisdat@th-wildau.de.
F
F
Lisdat
D015374:Biosensing Techniques / Q000379:methods*; D005708:Gallium / Q000737:chemistry; D007204:Indium / Q000737:chemistry; D009243:NAD / Q000737:chemistry / Q000302:isolation & purification*; D049329:Nanostructures / Q000737:chemistry; D053770:Nanowires / Q000737:chemistry*
D007204:Indium; D009243:NAD; D005708:Gallium
InGaN/GaN nanowires; NADH sensing; Photoelectrochemical sensor; Photoelectrochemistry