Microchip Based Determination of Bacteria by in-Chip Sandwich Immunoassay

Kasap, Esin Nagihan
Çoğun, Ferah
Yıldırım, Ender
Doğan, Üzeyir
Boyacı, İsmail Hakkı
Çetin, Demet
Suludere, Zekiye
Tamer, Uğur
Ertaş, Nusret
Bacteria detection is still a challenging issue and conventional bacterial detection methods are time consuming. In this study, a passive microchip design was used for fast and sensitive determination of Escherichia Coli (E. Coli) based on sandwich immunoassay. Gold coated magnetic nanoparticles (MNPs) and cadmium telluride (CdTe) quantum dots (QDs) were synthesized, surface modified and functionalized using E.coli specific antibody and they were used to form an in-chip sandwich immunoassay. The developed microchip consists of four micro-chambers connected to each other by microchannels, which act as capillary valves. First the magnetic separation and preconcentration of the E.coli from the sample solution in the vial was performed and then, the first chamber was filled with MNP-bacteria conjugate. The second microchamber was filled with QD-antibody conjugate, the third and fourth chambers were filled with washing buffer (phosphate buffered saline, pH=7.4). The MNP-bacteria conjugates were transferred from the first chamber through the microchannel using a magnet and being interacted with the QDs and then, washed in the third chamber in order to eliminate free QDs. Signal measurement was performed at the forth chamber using hand held spectrofluorometer equipped with a 295 nm LED source for excitation and fiber optic reflection probe. Amount of MNP and QDs injected to the microchambers were optimized. The calibration was linear in the range of 101 -105 cfu/mL with a correlation coefficient higher than 0.988. River water samples were analyzed with a recovery of 92 ± 10 %. The detection limit of the method in PBS was calculated as 1 cfu/mL. The proposed technique provides an inexpensive, rapid and sensitive method for the determination of E. coli.
10th Aegean Analytical Chemistry Days, (29 Eylül - 02 Ekim 2016)


Microbial Community Degradation of Widely Used Quaternary Ammonium Disinfectants
Oh, Seungdae; Kurt, Zöhre; Tsementzi, Despina; Weigand, Michael R.; Kim, Minjae; Hatt, Janet K.; Tandukar, Madan; Pavlostathis, Spyros G.; Spain, Jim C.; Konstantinidis, Konstantinos T. (American Society for Microbiology, 2014-10-01)
Benzalkonium chlorides (BACs) are disinfectants widely used in a variety of clinical and environmental settings to prevent microbial infections, and they are frequently detected in nontarget environments, such as aquatic and engineered biological systems, even at toxic levels. Therefore, microbial degradation of BACs has important ramifications for alleviating disinfectant toxicity in nontarget environments as well as compromising disinfectant efficacy in target environments. However, how natural microbial ...
Recombinant plasmid-based quantitative Real-Time PCR analysis of Salmonella enterica serotypes and its application to milk samples
Gokduman, Kurtulus; AVŞAROĞLU ERKAN, MÜRŞİDE DİLEK; Cakiris, Aris; Ustek, Duran; Gültekin, Güzin Candan (Elsevier BV, 2016-03-01)
The aim of the current study was to develop, a new, rapid, sensitive and quantitative Salmonella detection method using a Real-Time PCR technique based on an inexpensive, easy to produce, convenient and standardized recombinant plasmid positive control. To achieve this, two recombinant plasmids were constructed as reference molecules by cloning the two most commonly used Salmonella-specific target gene regions, invA and ttrRSBC The more rapid detection enabled by the developed method (21 h) compared to the ...
Antibiotic loaded nanocapsules functionalized with aptamer gates for targeted destruction of pathogens
Kavruk, M.; ÇELİKBIÇAK, ÖMÜR; Ozalp, V. C.; Borsa, B. A.; Hernandez, F. J.; BAYRAMOĞLU, GÜLAY; SALİH, BEKİR; ARICA, MEHMET YAKUP (2015-01-01)
In this study, we designed aptamer-gated nanocapsules for the specific targeting of cargo to bacteria with controlled release of antibiotics based on aptamer-receptor interactions. Aptamer-gates caused a specific decrease in minimum inhibitory concentration (MIC) values of vancomycin for Staphylococcus aureus when mesoporous silica nanoparticles (MSNs) were used for bacteria-targeted delivery.
Determination of colistin resistance in Escherichia coli isolates from foods in Turkey, 2011-2015
Güzel, Mustafa; Avşaroğlu, M Dilek; Soyer, Yeşim (2020-05-01)
Antimicrobial resistance of pathogenic microorganisms is an emerging public health concern. Intensive use of antibiotics in food animals might increase antimicrobial resistance in foodborne pathogens. Colistin is a last resort antibiotic for treatment of multidrug resistant (MDR) Gram negative pathogens. The recent antimicrobial resistance studies revealed a mobile antimicrobial resistance gene (mcr) that provides resistance to colistin. Furthermore, the gene has been found in different genera. Therefore, t...
Fabrication and in vitro characterization of antibacterial magneto-luminescent core-shell bioactive glass nanoparticles
Unal, Fatma; Tasar, Cansu; Ercan, Batur (2023-01-01)
When nanomaterials with antibacterial properties were sent to the infected area, it was predicted that infection and related complications could be prevented. The nanoparticles can be designed to possess magnetic and luminescence (magneto-luminescent) properties to be effectively targeted and localized at the infection foci without dispersing into the body. Simultaneously, the magneto-luminescent characteristic of particles allows visualization and confirmation of localized particles at the desired area. In...
Citation Formats
E. N. Kasap et al., “Microchip Based Determination of Bacteria by in-Chip Sandwich Immunoassay,” Çanakkale, Türkiye, 2016, p. 31, Accessed: 00, 2021. [Online]. Available: http://aacd2016.comu.edu.tr/announcements/abstract_book_of_aac.