Quartz crystal microbalance–based aptasensor integrated with magnetic pre‑concentration system for detection of Listeria monocytogenes in food samples


A fast and accurate identifcation of Listeria monocytogenes. A new quartz crystal microbalance (QCM) aptasensor was designed for the specific and rapid detection of L. monocytogenes. Before detection of the target bacterium from samples inthe QCM aptasensor, a magnetic pre-enrichment system was used to eliminate any contaminant in the samples. The preparedmagnetic system was characterized using ATR-FTIR, SEM, VSM, BET, and analytical methods. The saturation magnetizationvalues of the Fe3O4, Fe3O4@PDA, and Fe3O4@PDA@DAPEG particles were 57.2, 40.8, and 36.4 emu/g, respectively.The same aptamer was also immobilized on the QCM crystal integrated into QCM flow cell and utilized to quantitativelydetect L. monocytogenes cells from the samples. It was found that a specific aptamer-magnetic pre-concentration systemefficiently captured L. monocytogenes cells in a short time approximately 10 min). The Fe3O4@PDA@DA-PEG-Apt particlesprovided selective isolation of L. monocytogenes from the bacteria-spiked media up to 91.8%. The immobilized aptamercontent of the magnetic particles was 5834 μg/g using 500 ng Apt/mL. The QCM aptasensor showed a very high range ofanalytical performance to the target bacterium from 1.0 × 102and 1.0 × 107CFU/mL. The limit of detection (LOD) and limit of quantitation (LOQ) were 148 and 448 CFU/mL, respectively, from the feeding of the QCM aptasensor flow cell with the eluent of the magnetic pre-concentration system. The reproducibility of the aptasensor was more than 95%. The aptasensor was very specific to L. monocytogenes compared to the other Listeria species (i.e., L. ivanovii, L. innocua, and L. seeligeri) or other tested bacteria such as Staphylococcus aureus, Escherichia coli, and Bacillus subtilis. The QCM aptasensor was regenerated with NaOH solution, and the system was reused many times.


Open Access; Published by Microchimica Acta;; Fatma Beyazit, Department of Obstetrics and Gynecology, Faculty of Medicine, Çanakkale Onsekiz Mart University, Çanakkale, Turkey; Mehmet Yakup Arica, Biochemical Processing and Biomaterial Research Laboratory, Gazi University, 06500 Teknikokullar, Ankara, Turkey; · Ilkay Acikgoz‑Erkaya, Department of Environmental Science, Faculty of Engineering and Architecture, Ahi Evran University, Kırsehir, Turkey; Cengiz Ozalp, Department of Medical Biology, School of Medicine, Atilim University, Ankara, Turkey; Gulay Bayramoglu, Biochemical Processing and Biomaterial Research Laboratory, Gazi University, 06500 Teknikokullar, Ankara, Turkey, Department of Chemistry, Faculty of Sciences, Gazi University, 06500 Teknikokullar, Ankara, Turkey.


Magnetic particles, Pre-concentration, Aptasensor, Quartz crystal microbalance, Listeria monocytogenes