Premium
Photoelectrochemical versus Electrochemical Detection of H 2 O 2 Using an All‐inorganic Sensor Based on Nanostructured Copper Oxide
Author(s) -
Rehosek Marco,
Mitoraj Dariusz,
Bledowski Michal,
Beranek Radim
Publication year - 2016
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.201600227
Subject(s) - electrochemistry , materials science , detection limit , electrochemical gas sensor , photoelectrochemistry , analytical chemistry (journal) , semiconductor , inorganic chemistry , optoelectronics , chemistry , electrode , chromatography
All‐inorganic nanostructured CuO sensors for both electrochemical and photolectrochemical detection of H 2 O 2 were fabricated by electrodeposition and annealing, and compared in terms of their sensing properties. The calibration curves showed an excellent linearity in the H 2 O 2 concentration range of 0.1–1.0 mM, with strong correlation in both electrochemical (R 2 >0.999) and photolectrochemical (R 2 >0.990) mode. The higher quality of the linear correlation in the electrochemical mode resulted in the lower limit of detection (LOD) of 0.06 mM, as compared to 0.18 mM in the photoelectrochemical mode. The sensitivity in the electrochemical and photoelectrochemical mode was −73.7 µA cm −2 mM −1 and −46.4 µA cm −2 mM −1 , respectively. The signal‐to‐noise ratio, performance stability, and selectivity in the presence of various interference compounds (catechol, cysteine, dopamine, nitrate, and uric acid) were found to be better in the photoelectrochemical mode. The photoaction spectra of the photoelectrochemical CuO sensor revealed a maximum in visible light ( λ ∼450 nm) which is advantageous in terms of the possibility to use low‐cost and highly stable light sources (LEDs). The demonstrated differences of sensor operation in different modes show that a careful analysis is necessary for realistic evaluation of distinct advantages associated with operation of sensors based on nanostructured semiconductors in either electrochemical or photoelectrochemical mode.