Operating characteristics and comparison of photopyroelectric and piezoelectric sensors for trace hydrogen gas detection. II. Piezoelectric quartz‐crystal microbalance sensor

1989 ◽  
Vol 66 (9) ◽  
pp. 3986-3992 ◽  
Author(s):  
Constantinos Christofides ◽  
Andreas Mandelis
2006 ◽  
Vol 52 (12) ◽  
pp. 2273-2280 ◽  
Author(s):  
Yang Luo ◽  
Ming Chen ◽  
Qianjun Wen ◽  
Meng Zhao ◽  
Bo Zhang ◽  
...  

Abstract Background: Urinary proteins are predictive and prognostic markers for diabetes nephropathy. Conventional methods for the quantification of urinary proteins, however, are time-consuming, and most require radioactive labeling. We designed a label-free piezoelectric quartz crystal microbalance (QCM) immunosensor array to simultaneously quantify 4 urinary proteins. Methods: We constructed a 2 × 5 model piezoelectric immunosensor array fabricated with disposable quartz crystals for quantification of microalbumin, α1-microglobulin, β2-microglobulin, and IgG in urine. We made calibration curves after immobilization of antibodies at an optimal concentration and then evaluated the performance characteristics of the immunosensor with a series of tests. In addition, we measured 124 urine samples with both QCM immunosensor array and immunonephelometry to assess the correlation between the 2 methods. Results: With the QCM immunosensor array, we were able to quantify 4 urinary proteins within 15 min. This method had an analytical interval of 0.01–60 mg/L. The intraassay and interassay imprecisions (CVs) were <10%, and the relative recovery rates were 90.3%–109.1%. Nonspecificity of the immunosensor was insignificant (frequency shifts <20 Hz). ROC analyses indicated sensitivities were ≥95.8% and, specificities were ≥76.3%. Bland–Altman difference plots showed the immunosensor array to be highly comparable to immunonephelometry. Conclusions: The QCM system we designed has the advantages of being rapid, label free, and highly sensitive and thus can be a useful supplement to commercial assay methods in clinical chemistry.


1997 ◽  
Vol 30 (12) ◽  
pp. 2159-2174 ◽  
Author(s):  
Orliney M. Guimarães ◽  
José F. Andrade ◽  
Denise P. Ruys

2018 ◽  
Vol 4 (3) ◽  
pp. 264
Author(s):  
Gede Wibawa ◽  
Rica Widi Lestari ◽  
Sofia Wardhani

The Piezoelectric Quartz Crystal Microbalance (QCM) method was used to measure the solubilities of n-amylalcohol in poly (n-butyl methac1ylate) and polyisobutylene at temperatures of 333.15 K, 353.15 K and 353.15 K. The crystals used were 5 MHz, AT-Cut, 5.5 mm in diameter and 0.3 mm in thick. Reliability of the measurements was comfirmed by comparing the present data with the literature data for the system of benzene-polyisobutylene at temperature 338.15K. The solubilities n-amyl alcohol in polyisobutylene were undectedable in the range of temperature experiments by the present apparatus because of the low solubility. For the solubilities of n-amyl alcohol in ploy (n-butyl methacryalate) the higher temperature, the lower solubility and the experimental data could be correlated by the UNIQUAC equation with average absolute deviation between experimental and calculated solvent activities of 3.8%. Keywords: Solubility, Quartz Crystal Microbalance, Solvent, Polymer AbstrakDalam penelitian ini, metode Piezoelectric Quartz Crystal Microbalance (QCM) digunakan untuk mengukur kelarutan pelarut n-amylalkohol dalam polimer poly (n-butyl methacrylate) dan polyisobutylene pada temperatur 333,15 K, 343,15 K dan 353,15 K. Kristal yang digunakan adalah jenis AT-Cut 5 MHz, diameter 5,5 mm dan ketebalan 0,3 mm. Reliabilitas dari pengukuran di tes dengan membandingkan hasil pengukuran dengan data literatur untuk sistem benzene­polyisobutylene pada temperatur 338, I 5K. Kelarutan n-amyl alkohol dalam polyisobutylene tidak dapat terdeteksi pada range temperatur eksperimen dengan peralatan yang ada karena kelarutannya rendah. Untuk kelarutan n-amylalkohol dalam poly(n-butyl methacrylate), semakin besar suhu, kelarutannya semakin rendah dan data eksperimen dapat dikorelasikan menggunakan persamaan UNIQUAC dengan rata-rata deviasi ahsolut sebesar 3,8%.Kata Kunci: Kelarutan, Quartz Crystal Microbalance, Pelarut, Polimer


2012 ◽  
Vol 7 (2) ◽  
pp. 155892501200700 ◽  
Author(s):  
Didem Rodoplu ◽  
Mehmet Mutlu

To improve the performance of mass sensitive biosensors, the surface of a piezoelectric quartz crystal transducer, is expanded by employing electrospun nanofibers to its surface. This work describes the effect of vertical - horizontal electrospinning setups and electrospinning parameters on fiber morphology. The research objective was to obtain finer and non-beaded fiber morphologies, via controllable and repeatable process parameters, for further applications of QCM surfaces in high performance DNA-, Aptamer-, Immunosensor applications.


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