Layer-by-Layer Films with CoFe2O4Nanocrystals and Graphene Oxide as a Sensitive Interface in Capacitive Field-Effect Devices
Sensor devices have proved to be a promising technology for portable microelectronic systems for biomedical and environmental applications. Depending on the target analyte and/or the sensor platform chosen, the study of (nano)materials and their ideal incorporation in the device as a receptor layer...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2022 |
| País: | Brasil |
| Institución: | Universidade Estadual Paulista (UNESP) |
| Repositorio: | Repositório Institucional da UNESP |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.unesp.br:11449/223761 |
| Acceso en línea: | http://dx.doi.org/10.1021/acsanm.2c00296 http://hdl.handle.net/11449/223761 |
| Access Level: | acceso abierto |
| Palabra clave: | CoFe2O4nanocrystals EIS sensors field-effect devices graphene oxide layer-by-layer technique nanostructured films |
| Sumario: | Sensor devices have proved to be a promising technology for portable microelectronic systems for biomedical and environmental applications. Depending on the target analyte and/or the sensor platform chosen, the study of (nano)materials and their ideal incorporation in the device as a receptor layer have great importance for developing sensing units with enhanced properties and performance. Here, we employed the layer-by-layer (LbL) technique to fabricate nanostructured films as sensing units for detecting H2O2 and heavy metal ions (Cd2+ and Cu2+). The LbL film was deposited on electrolyte-insulator-semiconductor (EIS) field-effect devices, combining CoFe2O4 nanocrystals embedded into polyallylamine hydrochloride (PAH) and graphene oxide (GO) as a PAH-CoFe2O4/GO structure. Scanning electron microscopy revealed a LbL film morphology with high surface area presenting heterogeneous clusters of nanocrystals covered by a homogeneous coating of GO. The electrochemical characterization to monitor the film growth and the sensing properties for detecting H2O2 and Cd2+ and Cu2+ ions was carried out by capacitance-voltage (C/V) and constant-capacitance (ConCap) measurements. The results demonstrated catalytic features in detection experiments for an optimized EIS-LbL sensor containing a 6-bilayer PAH-CoFe2O4/GO LbL film. This sensor system was sensitive for all analytes and exhibited a low limit of detection of ca. 314.3 µM for H2O2 and 0.54 and 0.47 µM for Cd2+ and Cu2+ ions, respectively. These findings prove the relevance of incorporating nanostructured films as a receptor layer to enhance sensing properties and may envisage a proof-of-concept field-effect sensor system for environmental applications. |
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