Title :
Optical electronic nose based on porphyrin and phthalocyanine thin films for rice flavour classification
Author :
Palasuek, Rotthaporn ; Kladsomboon, Sumana ; Thepudom, Treenet ; Kerdcharoen, Teerakiat
Author_Institution :
Mater. Sci. & Eng. Programme, Mahidol Univ., Bangkok, Thailand
Abstract :
In this paper, we have developed an optoelectronic nose for rice classification based on measurement of changes in the optical absorption of organic thin films upon interactions with volatile analytes. The organic thin films based on metalloporphyrin (ZnTPP) and metallophthalocyanine (ZnOBPc) for gas sensing application were fabricated by spin coating technique. The optical properties of these thin films were tested with UV-VIS spectrophotometry. The surface topology of the films was observed by atomic force microscopy (AFM) technique which reveals that the film´s topology is homogeneous with nano-scale thickness. The sensing behavior of the films toward various volatile compounds representing the simulated aroma rice, such as 5% v/v hexanal, 5% v/v octanal and deionized water, was investigated under N2 atmosphere at room temperature. The results have shown that ZnTPP and ZnOBPc thin film gas sensors can discriminate such volatile compounds. The optoelectronic nose was then applied to examine the odors of Jasmine rice, normal white rice and various of their mixtures. It was shown that ZnOBPc thin film can clearly classify the type of rice better than ZnTPP thin film. These results were confirmed by computational quantum mechanics based on density functional theory, which reveals that ZnOBPc molecule binds to the simulated rice aroma molecules better than ZnTPP molecule.
Keywords :
atomic force microscopy; crops; density functional theory; electronic noses; nanophotonics; nanosensors; optical sensors; optoelectronic devices; polymer films; quantum theory; spectrophotometry; spin coating; thin film sensors; ultraviolet spectroscopy; visible spectroscopy; AFM; Jasmine rice; OBPc thin film gas sensor; UV-VIS spectrophotometry; ZnOBPc molecule binding; ZnTPP thin film gas sensor; atomic force microscopy; density functional theory; films topology; gas sensing application; metallophthalocyanine; metalloporphyrin; nanoscale thickness; normal white rice; optical absorption measurement; optical electronic nose; optoelectronic nose; organic thin films; phthalocyanine thin film; porphyrin thin film; quantum mechanics; rice flavour classification; simulated aroma rice; spin coating technique; surface topology; volatile analytes; volatile compounds; Conferences; Information processing; Intelligent sensors; Electronic nose; Food sensor; Optical gas sensor; Phthalocyanine; Porphyrin; Rice;
Conference_Titel :
Intelligent Sensors, Sensor Networks and Information Processing (ISSNIP), 2014 IEEE Ninth International Conference on
Conference_Location :
Singapore
Print_ISBN :
978-1-4799-2842-2
DOI :
10.1109/ISSNIP.2014.6827644