scholarly journals Molecular Imprinting of Bisphenol A on Silica Skeleton and Gold Pinhole Surfaces in 2D Colloidal Inverse Opal through Thermal Graft Copolymerization

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1892
Author(s):  
Jin Chul Yang ◽  
Jinyoung Park
Keyword(s):  
Quartz Crystal ◽  
Silica Surface ◽  
Freundlich Isotherm ◽  
Gold Surface ◽  
Frequency Change ◽  
Inverse Opal ◽  
Bisphenol F ◽  
Bpa Detection ◽  
Silica Skeleton ◽  
Linear Regressions

This study successfully fabricated BPA-imprinted poly(4-vinylpyridine-co-ethylene glycol dimethacrylate) (poly(4-VP-co-EGDMA)) quartz crystal microbalance (MIP-QCM) sensors on a silica skeleton surface and gold pinholes of silica inverse opal through surface-initiated atom transfer radical polymerization (SI-ATRP). The sensing features of the two MIP films on the structured silica surface and nano-scale local gold surface were investigated by measuring the resonant frequency change (∆f) in QCM sensors. The ∆f values for the p-MIP (MIP on gold pinholes) and s-MIP films (MIP on silica skeleton surface) were obtained with the ∆f value of −199 ± 4.9 Hz and −376 ± 19.1 Hz, respectively, whereas for p-/s-NIP films, the ∆f values were observed to be −115 ± 19.2 Hz and −174 ± 5.8 Hz by the influence of non-specific adsorption on the surface of the films. Additionally, the imprinting factor (IF) appeared to be 1.72 for p-MIP film and 2.15 for s-MIP film, and the limits of quantitation (LOQ) and detection (LOD) were 54.924 and 18.125 nM (p-MIP film) and 38.419 and 12.678 nM (s-MIP film), respectively. Using the Freundlich isotherm model, the binding affinity of the BPA-imprinted films was evaluated. This was measured in an aqueous solution of BPA whose concentration ranged between 45 and 225 nM. It was found that the p-MIP film (m = 0.39) was relatively more heterogeneous than the s-MIP film (m = 0.33), both of which were obtained from the slope of the linear regressions. Finally, the selectivity of the MIP-QCM sensors for BPA detection was determined by measuring the effect of other analogous chemicals, such as bisphenol F (BPF), bisphenol AP (BPAP), and bisphenol B (BPB), in aqueous solutions. The selectivity coefficients (k*) of the two MIP films had ~1.9 for the p-MIP and ~2.3 for the s-MIP films, respectively. The results reveal that, with respect to signal amplification of the QCM sensors, the s-MIP film has better sensing features and faster detection responses than the p-MIP film.

THE ELECTROCHEMICAL STUDIES ON A SELF-ASSEMBLED VIOLOGEN MONOLAYER USING QUARTZ CRYSTAL MICROBALANCE

2002 ◽  
Vol 01 (05n06) ◽  
pp. 593-596 ◽  
Author(s):  
J. Y. OCK ◽  
H. K. SHIN ◽  
Y. S. KWON ◽  
S. H. SONG ◽  
S. M. CHANG ◽  
...  
Keyword(s):  
Self Assembly ◽  
Quartz Crystal ◽  
Surface Coverage ◽  
Gold Surface ◽  
Frequency Change ◽  
Self Assembled Monolayer ◽  
Solution Interface ◽  
Reversible Redox ◽  
Mass Detector ◽  
Self Assembled

The electrochemical behavior of viologen self-assembled monolayer has been investigated with QCM, which has been known as ng order mass detector. The self-assembly process of viologen was monitored using resonant frequency (ΔF) and resonant resistance (R). The QCM measurements indicated a mass adsorption for viologen assembling on the gold surface with a frequency change of about 300, 135 Hz and its surface coverage (Γ) was calculated to be 5.02 × 10-9 and 1.64 × 10-9 mol/cm2. A reversible redox process was also observed and analyzed with an ionic interaction at the viologen/solution interface using ΔF.

scholarly journals Quantitative Assessment of Periodontal Bacteria Using a Cell-Based Immunoassay with Functionalized Quartz Crystal Microbalance

Chemosensors ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 159
Author(s):  
Satit Rodphukdeekul ◽  
Miyuki Tabata ◽  
Chindanai Ratanaporncharoen ◽  
Yasuo Takeuchi ◽  
Pakpum Somboon ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Quartz Crystal Microbalance ◽  
Quantitative Assessment ◽  
Quartz Crystal ◽  
Dynamic Range ◽  
Gold Surface ◽  
Enzyme Linked Immunosorbent Assay ◽  
Inflammatory Disorder ◽  
Label Free ◽  
Periodontal Bacteria

Periodontal disease is an inflammatory disorder that is triggered by bacterial plaque and causes the destruction of the tooth-supporting tissues leading to tooth loss. Several bacteria species, including Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, are considered to be associated with severe periodontal conditions. In this study, we demonstrated a quartz crystal microbalance (QCM) immunoassay for quantitative assessment of the periodontal bacteria, A. actinomycetemcomitans. An immunosensor was constructed using a self-assembled monolayer of 11-mercaptoundecanoic acid (11-MUA) on the gold surface of a QCM chip. The 11-MUA layer was evaluated using a cyclic voltammetry technique to determine its mass and packing density. Next, a monoclonal antibody was covalently linked to 11-MUA using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide to act as the biorecognition element. The specificity of the monoclonal antibody was confirmed by an enzyme-linked immunosorbent assay. A calibration curve, for the relationship between the frequency shifts and number of bacteria, was used to calculate the number of A. actinomycetemcomitans bacteria in a test sample. Based on a regression equation, the lower detection limit was 800 cells, with a dynamic range up to 2.32 × 106 cells. Thus, the QCM biosensor in this study provides a sensitive and label-free method for quantitative analysis of periodontal bacteria. The method can be used in various biosensing assays for practical application and routine detection of periodontitis pathogens.

Frequency Change of Quartz Crystal Resonator Caused during Ion Beam Etching

2007 ◽  
Vol 46 (7B) ◽  
pp. 4647-4651 ◽  
Author(s):  
Tadahisa Shiono ◽  
Yuusuke Osada ◽  
Yasuhiko Nakagawa
Keyword(s):  
Quartz Crystal ◽  
Ion Beam ◽  
Frequency Change ◽  
Quartz Crystal Resonator ◽  
Ion Beam Etching ◽  
Crystal Resonator

Cellular Adhesion and Spreading of Endothelial Cells Monitored in Real Time Using the Quartz Crystal Microbalance

1998 ◽  
Vol 550 ◽  
Author(s):  
Tiean Zhou ◽  
Susan J. Braunhut ◽  
Diane Medeiros ◽  
Kenneth A. Marx
Keyword(s):  
Endothelial Cells ◽  
Quartz Crystal Microbalance ◽  
Quartz Crystal ◽  
Cell Mass ◽  
Viscoelastic Behavior ◽  
Cellular Adhesion ◽  
Frequency Change ◽  
Resistance Change ◽  
Continuous Increase ◽  
Mock Cell

AbstractWe have applied the Quartz Crystal Microbalance (QCM) technique to continuously record the processes of endothelial cell (EC) adhesion, spreading and cellular mass distribution changes during initial cell to surface contact and homeostatic attachment. ECs (50,000) were layered onto a set volume of media in the QCM device and simultaneously in a mock cell used for photomicroscopy. As cells were observed in the mock cell device to contact and attach to the surface over 45-55 min, we measured in the QCM device a continuous decrease in frequency and continuous increase in resistance, achieving a maximum at about one hr (1400 Ω frequency change and 1400 Ω motional resistance change). These frequency and resistance values stabilized over the next 24 hrs and were unchanged out to 72 hr by QCM measurement (to ∼700 Hz, ∼700 Ω), as the cells were observed to spread in the mock device. Both bovine aortic (BAE) and bovine capillary (BCE) endothelial cells were studied and found to exhibit similar behavior. These studies demonstrate that QCM can be used to detect continuous changes in cell mass and viscoelastic behavior.

Fabrication of Ethanol Sensor Based on a Calixarene Derivative Coated Piezoelectric Quartz Crystal

2010 ◽  
Vol 139-141 ◽  
pp. 2262-2265
Author(s):  
Yun Lin Dai ◽  
Zhong Cao ◽  
Yi Min Dai ◽  
Ju Lan Zeng ◽  
Wei Gang Huang ◽  
...  
Keyword(s):  
Quartz Crystal ◽  
Practical Purpose ◽  
Gold Surface ◽  
Ethanol Vapor ◽  
Ethanol Sensor ◽  
Recognition Mechanism ◽  
Piezoelectric Quartz ◽  
Calixarene Derivative ◽  
On Line ◽  
Piezoelectric Quartz Crystal

Coating with a calixarene derivative on gold surface of AT-cut quartz crystal, a piezoelectric quartz crystal (PQC) sensing device was successfully fabricated in this paper. Among four calixarene materials, the compound of MRCT was the most efficient actively coating material for recognizing ethanol molecule based on a host-guest recognition mechanism with C—H•••π interaction. In comparison with gas-chromatography (GC) method, the calixarene based PQC device can be well used for on-line detection of the ethanol vapor in the range of 0 ~ 3000 ppm around our environment with a recovery of 92.33~105.76 %. The detection limit can be evaluated to be 3.53 ppm. Furthermore, the proposed TSM sensor possessed good selectivity, reproducibility, reversibility and high stability for practical purpose.

FORMATION OF GOLD NANOPARTICLES/OLIGOTHIOPHENE DITHIOLS COMPOSITE THIN FILMS BETWEEN MICROGAPPED GOLD ELECTRODES AND THEIR ELECTRONIC PROPERTIES

2002 ◽  
Vol 01 (05n06) ◽  
pp. 557-562 ◽  
Author(s):  
SEISUKE MAEDA ◽  
TAKUJI OGAWA
Keyword(s):  
Gold Nanoparticles ◽  
Coulomb Blockade ◽  
Gold Electrode ◽  
Quartz Crystal ◽  
Gold Surface ◽  
Crystal Oscillator ◽  
Tunneling Mechanism ◽  
Straight Line ◽  
Current Voltage ◽  
Lower Temperature

We have studied the construction and electronic characteristics of a series of devices made from gold microgap electrodes, gold nanoparticles and conjugated oligothiophene dithiols. The formations of gold nanoparticle/oligothiophene dithiol composites on gold surface were monitored by quartz crystal microbalance (QCM) using gold electrode coated crystal oscillator. The formation speed was the fastest for terthiophene dithiol followed by hexathiophene and nanothiophene dithiols, the latter two showed almost the same formation speed. The current–voltage (I/V) curves of these devices were measured at various temperatures to show that at high temperature (>200 K) they were almost straight line; at lower temperature they became parabolic, and at 4 K a completely blocked region appeared between -12 to +12 V. We attributed the parabolic I/V curve to a tunneling mechanism and the blocked region to the Coulomb blockade phenomena.

Charge Transfer Property of Self-Assembled Viologen Derivative by Electrochemical Quartz Crystal Microbalance Response

2006 ◽  
Vol 6 (11) ◽  
pp. 3657-3660 ◽  
Author(s):  
Dong-Yun Lee ◽  
A. K. M. Kafi ◽  
Sang-Hyun Park ◽  
Young-Soo Kwon
Keyword(s):  
Charge Transfer ◽  
Quartz Crystal Microbalance ◽  
Quartz Crystal ◽  
Modified Electrodes ◽  
Electrochemical Quartz Crystal Microbalance ◽  
Frequency Change ◽  
Self Assembled Monolayer ◽  
Transfer Property ◽  
Redox Peak ◽  
Self Assembled

Viologen modified electrodes have been extensively investigated with quartz crystal microbalance (QCM), which has been known as a nano-gram order mass detector, because of their highly reversible electrochemical properties, especially the first reduction-oxidation cycle of V2+ ↔ V•+. The purpose of this work was to study the charge transfer characteristics of self-assembled monolayer (SAM) by changing electrolyte solutions where the cations and anions are different. The redox peak currents were nearly equal charges during redox processes and showed an excellent linear interrelation between the scan rates and second redox peak currents. The charge transfer of self-assembled viologen monolayer was determined by the mass change during the cyclic voltammetry (CV). The total frequency change was about 17.8 Hz, 19.6 Hz, 9.5 Hz, and 8.4 Hz. From this data, we could know the transferred mass was about 19.0 ng, 20.9 ng, 10.2 ng, and 9.0 ng. Finally, the electrochemical quartz crystal microbalance (EQCM) has been employed to monitor the electrochemically induced adsorption of self-assembled monolayer.

Fabrication of hydroxyapatite ultra-thin layer on gold surface and its application for quartz crystal microbalance technique

Biomaterials ◽  
2006 ◽  
Vol 27 (33) ◽  
pp. 5748-5754 ◽  
Author(s):  
Akira Monkawa ◽  
Toshiyuki Ikoma ◽  
Shunji Yunoki ◽  
Tomohiko Yoshioka ◽  
Junzo Tanaka ◽  
...  
Keyword(s):  
Thin Layer ◽  
Quartz Crystal Microbalance ◽  
Quartz Crystal ◽  
Gold Surface
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