An Impedance-Based Mold Sensor with on-Chip Optical Reference.
A new miniaturized sensor system with an internal optical reference for the detection of mold growth is presented. The sensor chip comprises a reaction chamber provided with a culture medium that promotes the growth of mold species from mold spores. The mold detection is performed by measuring impedance changes with integrated electrodes fabricated inside the reaction chamber. The impedance change in the culture medium is caused by shifts in the pH (i.e., from 5.5 to 8) as the mold grows. In order to determine the absolute pH value without the need for calibration, a methyl red indicator dye has been added to the culture medium. It changes the color of the medium as the pH passes specific values. This colorimetric principle now acts as a reference measurement. It also allows the sensitivity of the impedance sensor to be established in terms of impedance change per pH unit. Major mold species that are involved in the contamination of food, paper and indoor environments, likeFusarium oxysporum,Fusarium incarnatum,Eurotium amstelodami,Aspergillus penicillioidesandAspergillus restrictus, have been successfully analyzed on-chip.
Institute for Microsensors, Actuators and Systems (IMSAS), University of Bremen, Otto-Hahn-Allee NW1, Bremen 28359, Germany. pvinayaka@imsas.uni-bremen.de.|Microsystems Center Bremen (MCB), Bremen 28359, Germany. pvinayaka@imsas.uni-bremen.de.
Poornachandra
P
Papireddy Vinayaka
Institute for Microsensors, Actuators and Systems (IMSAS), University of Bremen, Otto-Hahn-Allee NW1, Bremen 28359, Germany. sdriesche@uni-bremen.de.|Microsystems Center Bremen (MCB), Bremen 28359, Germany. sdriesche@uni-bremen.de.
Sander
S
van den Driesche
Institute for Microsensors, Actuators and Systems (IMSAS), University of Bremen, Otto-Hahn-Allee NW1, Bremen 28359, Germany. rblank@imsas.uni-bremen.de.|Microsystems Center Bremen (MCB), Bremen 28359, Germany. rblank@imsas.uni-bremen.de.
Roland
R
Blank
Institute for Microsensors, Actuators and Systems (IMSAS), University of Bremen, Otto-Hahn-Allee NW1, Bremen 28359, Germany. wtahir@imsas.uni-bremen.de.|Microsystems Center Bremen (MCB), Bremen 28359, Germany. wtahir@imsas.uni-bremen.de.
Muhammad Waseem
MW
Tahir
microFAB Service GmbH, Bremen 28359, Germany. frodl@microfab.de.
Mathias
M
Frodl
Institute for Microsensors, Actuators and Systems (IMSAS), University of Bremen, Otto-Hahn-Allee NW1, Bremen 28359, Germany. wlang@imsas.uni-bremen.de.|Microsystems Center Bremen (MCB), Bremen 28359, Germany. wlang@imsas.uni-bremen.de.
Walter
W
Lang
Institute for Microsensors, Actuators and Systems (IMSAS), University of Bremen, Otto-Hahn-Allee NW1, Bremen 28359, Germany. mvellekoop@imsas.uni-bremen.de.|Microsystems Center Bremen (MCB), Bremen 28359, Germany. mvellekoop@imsas.uni-bremen.de.
Michael J
MJ
Vellekoop
archives; colorimetric; culture medium; impedance; mold; transport containers
Clin Microbiol Rev. 2003 Jan;16(1):144-72
12525430
J Allergy Clin Immunol. 2006 Feb;117(2):326-33
16514772
J Food Prot. 2000 Feb;63(2):281-91
10678438
Vet Q. 1999 Oct;21(4):115-20
10568000
Philos Trans A Math Phys Eng Sci. 2014 May 05;372(2017):20130312
24797139
Appl Environ Microbiol. 2001 Jun;67(6):2453-9
11375150
Int J Environ Health Res. 2014 Aug;24(4):320-40
24070332
Biotechnol Adv. 2008 Mar-Apr;26(2):135-50
18155870
Sci Total Environ. 2012 Nov 1;438:477-89
23032564
Environ Sci Technol. 2009 Aug 1;43(15):5857-63
19731688
Sensors (Basel). 2009;9(9):7111-31
22423205
Indoor Air. 2008 Apr;18(2):113-24
18333991
J Clin Microbiol. 2010 May;48(5):1924-5
20220162
Philos Trans A Math Phys Eng Sci. 2014 May 05;372(2017):20130302
24797131
Anal Bioanal Chem. 2011 Jun;400(7):1905-11
21442367
J Aerosol Sci. 2015 Dec 1;90:114-123
26806982
Bull Environ Contam Toxicol. 2003 Apr;70(4):753-60
12677387