| Full text | |
| Author(s): |
Shimizu, Flavio M.
;
Todao, Fagner R.
;
Gobbi, Angelo L.
;
Oliveira, Jr., Osvaldo N.
;
Garcia, Carlos D.
;
Lima, Renato S.
Total Authors: 6
|
| Document type: | Journal article |
| Source: | ACS SENSORS; v. 2, n. 7, p. 1027-1034, JUL 2017. |
| Web of Science Citations: | 13 |
| Abstract | |
Electronic tongues (e-tongues) are promising analytical devices for a variety of applications to address the challenges of quality control in water monitoring and industries of foods, beverages, and pharmaceuticals. A crucial drawback in the current e-tongues is the need to recalibrate the device when one or more sensing units (usually with modified surface) are replaced. Another downside is the necessity to perform subsequent surface modifications and analyses to each of the diverse sensing units, undermining the simplicity and velocity of the method. These features have prevented widespread commercial use of the e-tongues. In this paper, we introduce a microfluidic e-tongue that overcomes all such limitations. The key principle of global selectivity of the e-tongue was achieved by recording only a single response, namely, the equivalent admittance spectrum of an association of resistors in parallel. Such resistors consisted of five nonfunctionalized stainless steel microwires (sensing units), which were short-circuited and coated with gold, platinum, nickel, iron, and aluminum oxide films. The microwires were inserted in a chip composed of a single piece of polydimethylsiloxane (PDMS). Using impedance spectroscopy, the e-tongue was successfully applied in classification of basic tastes at a concentration below the threshold for the human tongue. In addition, our chip allowed the distinction of various chemicals used in oil industry. Finally, our cleanroom-free prototyping allows the mass production of chips with easily replaceable and reproducible sensing units. Hence, one can now envisage the widespread dissemination of e-tongues with fast and reproducible data. (AU) | |
| FAPESP's process: | 14/24126-6 - Microemulsification in Analytical Chemistry for the development of point-of-care platforms: study of intervening parameters and automation in microfluidics |
| Grantee: | Renato Sousa Lima |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 13/14262-7 - Nanostructured films from biologically-relevant materials |
| Grantee: | Osvaldo Novais de Oliveira Junior |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 12/15543-7 - Biosensors to detect Escherichia coli using the concept of an extended electronic tongue |
| Grantee: | FLAVIO MAKOTO SHIMIZU |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |