TY - JOUR
T1 - A highly sensitive photoelectrochemical sensor with polarity-switchable photocurrent for detection of trace hexavalent chromium
AU - Liu, Qingyuan
AU - Kim, Jungyoon
AU - Cui, Tianhong
N1 - Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/8/15
Y1 - 2020/8/15
N2 - Signal quenching photoelectrochemical sensors have attracted extensive research interests due to outstanding performance and simplicity in realization. This work proposes a photoelectrochemical sensor with photocurrent polarity-switchable property for highly selective and sensitive detection of trace hexavalent chromium (Cr(VI)) ion. Layer-by-layer self-assembled graphene intercalation layer and drop-coated TiO2 nanocrystalline film are successively deposited onto patterned Au/SiO2/Si electrodes. By facilitating the photon-excited electron-hole pair separation, graphene significantly enhances the intensity and stability of the device photocurrent. Coupled with light-sensitive quercetin and its specific interaction with Cr(VI), such sensors can selectively switch the photocurrent polarity from anodic to cathodic with increasing Cr(VI) concentration, resulting in a large sensing range from 1.4 ppb to 2592.3 ppb, with a low detection limit of 0.44 ppb. Featured by the facile fabrication process, low-cost materials, good selectivity, and stable photocurrent output, this sensor shows promising potential applications to on-site environment monitoring.
AB - Signal quenching photoelectrochemical sensors have attracted extensive research interests due to outstanding performance and simplicity in realization. This work proposes a photoelectrochemical sensor with photocurrent polarity-switchable property for highly selective and sensitive detection of trace hexavalent chromium (Cr(VI)) ion. Layer-by-layer self-assembled graphene intercalation layer and drop-coated TiO2 nanocrystalline film are successively deposited onto patterned Au/SiO2/Si electrodes. By facilitating the photon-excited electron-hole pair separation, graphene significantly enhances the intensity and stability of the device photocurrent. Coupled with light-sensitive quercetin and its specific interaction with Cr(VI), such sensors can selectively switch the photocurrent polarity from anodic to cathodic with increasing Cr(VI) concentration, resulting in a large sensing range from 1.4 ppb to 2592.3 ppb, with a low detection limit of 0.44 ppb. Featured by the facile fabrication process, low-cost materials, good selectivity, and stable photocurrent output, this sensor shows promising potential applications to on-site environment monitoring.
KW - Charge transport
KW - Graphene
KW - Hexavalent chromium
KW - Photocurrent polarity
KW - Photoelectrochemical sensing
KW - Titanium dioxide
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U2 - 10.1016/j.snb.2020.128181
DO - 10.1016/j.snb.2020.128181
M3 - Article
AN - SCOPUS:85084369078
SN - 0925-4005
VL - 317
JO - Sensors and Actuators, B: Chemical
JF - Sensors and Actuators, B: Chemical
M1 - 128181
ER -