• Korean Journal of Mineralogy and Petrology
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• v.34 no.4
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• pp.265-275
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• 2021

Findings of microplastics and nanoplastics from diverse natural environments have increased demand for research of the fate and transport of the potentially toxic plastic particles in soils and groundwater. Weathering of microplastics would generate a significant amount of nanoplastics, but nanoplastics research is scarce because of technical difficulties in detecting nanoplastics in environments and analyzing nanoplastics adsorption to mineral surfaces. In the current study, we tested a possibility using quartz crystal microbalance (QCM) for application to nanoplastics adsorption analysis on mineral surfaces. In silica (SiO₂)-packed column experiments, a measurable adsorption capacity for polystyrene nanoparticles often requires injection of unrealistically high ionic strengths or concentrated nanoplastic particles. The current test shows that QCM can measure polystyrene nanoplastics adsorbed onto SiO₂ surface under the low ionic strengths and nanoplastics concentrations, where typical column experiments cannot. QCM is a promising tool for understanding the interaction between nanoplastics and mineral surfaces and thus transport of nanoplastics in soils and groundwater.

• Proceedings of the Korean Biophysical Society Conference
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• 1996.07a
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• pp.44-44
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• 1996

Immunoserisor for the determination of LDL(Low-Density Lipoprotein) was developed by using quartz crystal microbalance(QCM) system. LDL is known to be a good indicator for the diagnosis of atherosclerosis and hypercholesterolemia. The immunosensor consists of four parts; detection cell, oscillating circuit, oscilloscope, and frequency counter, and this was interfaced with personal computer for signal processing. (omitted)

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.395-396
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• 2005

We fabricated self-assembled monolayers(SAMs) onto quartz crystal microbalance(QCM) using viologen, which has been widely used as electron acceptor and electron transfer mediator. We determined the time dependence to resonant frequency shift during self-assembly process and observed the morphology of self-assembled mono layers by STM and investigated the electrochemical behavior of SAMs by cyclic voltammetry. Electrochemical deposition of viologen was investigated using electrochemical quartz crystal microbalance(EQCM). The redox reactions of viologen were highly reversible and the EQCM has been employed to monitor the electrochemically induced adsorption of SAMs during the redox reactions.

• Journal of Sensor Science and Technology
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• v.16 no.2
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• pp.132-141
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• 2007

The purpose this research is to develop QCM (quartz crystal microbalance) biosensor for the determination of haptoglobin. Haptoglobin is an acute-phase protein with a hemoglobin-binding activity and has a potential to be used as a biomarker for infection or cancer. Haptoglobin level in milk has been used for the diagnosis of cow mastitis. In this study, anti-bovine haptoglobin antibody or bovine hemoglobin was chemically immobilized on the surface of the QCM, and the resulting sensor chips were tested for their response to samples containing haptoglobin at different concentrations. Concentration dependent frequency change was observed with both of the sensor chips. Especially, the sensor chip containing anti-bovine haptoglobin antibody showed sufficient sensitivity in the concentrations typically observed in the cows with mastitis.

• Journal of Sensor Science and Technology
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• v.25 no.6
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• pp.435-439
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• 2016

We report a novel detection technology for glycated hemoglobin (HbA1c) that is measured primarily to identify the three-month average plasma glucose concentration. In enzymatic measuring of glycated hemoglobin, the generated hydrogen peroxide was then used as a reducing agent of gold (III) for the synthesis of gold (0). Gold nanoparticles obtained from this novel approach were measured by optical and piezoelectric methods. In optical method, we have developed polymer based film-type sensor cartridge filled with all the reagents for glycated hemoglobin analysis and the cartridge worked very well having the detection limit of 0.53% of glycated hemoglobin. On the other hand, quartz crystal microbalance (QCM) sensors also have been developed to determine the abilities of surface modified QCM sensors at various levels of the concentration of glycated hemoglobin to bind gold nanoparticles and limit of detection was 0.90%. Finally, despite of relatively lower sensitivities of QCM sensor and film-type optical sensor than well-plate based optical detection, these two sensors were available to measure the glycated hemoglobin level for diabetes patients and normal person.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.698-698
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• 2003

• Applied Chemistry for Engineering
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• v.24 no.1
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• pp.24-30
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• 2013

The adsorption characteristics of cationic starches and starch-oligomers were investigated using the quartz crystal microbalance with dissipation monitoring (QCM-D). The adsorbed amount of modified starches was higher than that of cationic surfactants such as $C_{12{\sim}16}$ trimethylammonium bromide. Cationic starches did not show the tendency depending on the degree of cationic substitution and molecular weight. On the other hand, the softness of the adsorption layer increased with the molecular weight of cationic starches in a viscoelasticity terms. During the adsorption/desorption steps, the amount of adsorbed cationic surfactants was 4~9 times. On the other hand, the difference in the amount of adsorption of all the $C_1$ grafted cationic starches was just 0~50%. In addition, the rigidity of the adsorption layer of cationic surfactant in the desorption step decreased, while, that of cationic starches increased at the same condition.

• Journal of Applied Biological Chemistry
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• v.44 no.4
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• pp.163-166
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• 2001

Piezoelectric (PZ) crystal biosensor system was used to detect the DNA of food pathogenic Listeria monocytogenes. L. monocytogenes-specific DNA was multiplied via the polymerase chain reaction using LM1 oligonucleotide (5'-TTACGAATTAAAAAGGAGCG-3') and LM2 oligonucleotide (5'-TTAAATCAGCAGGGGTCTTT-3') as primers. DNA fragment of 161 bp, which was specific only for L. monocytogenes, was observed. To obtain a large amount of single-stranded DNA containing an SH group used for coupling to the gold electrode chemisorptively, LM1 oligonucleotide containing a mercaptohexyl group was utilized as a single strand PCR primer. The PCR product was immobilized onto the gold electrode of PZ crystal, and hybridization was monitored in quartz crystal microbalance (QCM) system by injecting the antisense single-stranded DNA of 161 nucleotides obtained via the single strand PCR using the unmodified LM2 primer. Approximately 70 Hz of frequency drop was observed in the QCM system in the case of two consecutive injections of $5{\mu}g$ of the antisense single-stranded DNA.

• Journal of Sensor Science and Technology
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• v.15 no.4
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• pp.269-276
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• 2006

This paper represents development of quartz crystal microbalance (QCM) and usage as a dew point sensor. The temperature of a quartz resonator was controlled precisely from $20^{\circ}C$ to $-30^{\circ}C$ with the ramping rate of $0.1^{\circ}C/s$ by using a custom-made crystal holder housing the quartz resonator associated with a thermoelectric cooler (Peltier cooler), which results in the working range from $15.2^{\circ}C$ to $-24.0^{\circ}C$ based on an accurate holder temperature compensation and temperature effect compensation process. The developed QCM dew point sensor and analysis techniques show very good sensing characteristics at measurement of moist air with the relative humidity from 10 %R.H. to 90 %R.H. generated by a divided-type humidity generator and the dew point temperatures were determined with an accuracy of less than ${\pm}0.18^{\circ}C$, which also showed good agreement with reference values in their error range.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.7
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• pp.3423-3426
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• 2012

Background: The objective of this study was to measure the antibody content of NuTu-19 ovarian cancer cells in serum samples using a quartz crystal microbalance (QCM) immunosensor. Materials and Methods: NuTu-19 cells were first cultured onto the electrode surfaces of crystals in Dulbecco's modified Eagle medium, and then specified amounts of immunized serum samples of immunized rabbit were also added. The change in mass caused by specific adsorbtion of antibodies of NuTu-19 to the surfaces of the crystals was detected. Results: The change in resonance frequency of crystals caused by immobilization of NuTu-19 cells was from 83 to 429Hz. The antibody content of NuTu-19 detected was 341ng/ul. The frequency shifts were linearly dependent on the amount of antibody mass in the range of 69 to 340ng. The positive detection rate and the negative detection rate were 80% and 100%, respectively. Conclusion: This immunoassay provides a viable alternative to other early ovarian cancer detection methods and is particularly suited for health screening of the general population.