Development of a Mass Sensitive Quartz Crystal Microbalance (QCM)-Based DNA biosensor using a 50 MHz electronic oscillator circuit

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Authors: G. García-Martínez, E. Bustabad, H. Perrot, C. Gabrielli, B. Bucur, M. Lazerges, D. Rose. L. Rodríguez-Pardo, J. Fariña, C. Compère, A. Arnau

Journal: Sensors (2011)

This work deals with the design of a high sensitivity DNA sequence detector using a 50 MHz quartz crystal microbalance (QCM) electronic oscillator circuit. The oscillator circuitry is based on Miller topology, which is able to work in damping media. Calibration and experimental study of frequency noise are carried out, finding that the designed sensor has a resolution of 7.1 ng/cm2 in dynamic conditions (with circulation of liquid). Then the oscillator is proved as DNA biosensor. Results show that the system is able to detect the presence of complementary target DNAs in a solution with high selectivity and sensitivity. DNA target concentrations higher of 50 ng/mL can be detected.

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Frequency-shift vs phase-shift characterization of in-liquid quartz crystal microbalance applications

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Authors: Y. Montagut, J.V. García, Y. Jiménez, C. March, A. Montoya, A. Arnau

Journal: Review of Scientific Instruments (2011)

 

The improvement of sensitivity in quartz crystal microbalance (QCM) applications has been addressed in the last decades by increasing the sensor fundamental frequency, following the increment of the frequency/mass sensitivity with the square of frequency predicted by Sauerbrey. However, this sensitivity improvement has not been completely transferred in terms of resolution. The decrease of frequency stability due to the increase of the phase noise, particularly in oscillators, made impossible to reach the expected resolution. A new concept of sensor characterization at constant frequency has been recently proposed. The validation of the new concept is presented in this work. An immunosensor application for the detection of a low molecular weight contaminant, the insecticide carbaryl, has been chosen for the validation. An, in principle, improved version of a balanced-bridge oscillator is validated for its use in liquids, and applied for the frequency shift characterization of the QCM immunosensor application. The classical frequency shift characterization is compared with the new phase-shift characterization concept and system proposed.

Validation of a phase-mass characterization concept and interface for acoustic biosensors

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Authors: Y. Montagut, J.V. García, Y. Jiménez, C. March, A. Montoya, A. Arnau

Journal: Sensors (2011)

Acoustic wave resonator techniques are widely used in in-liquid biochemical applications. The main challenges remaining are the improvement of sensitivity and limit of detection, as well as multianalysis capabilities and reliability. The sensitivity improvement issue has been addressed by increasing the sensor frequency, using different techniques such as high fundamental frequency quartz crystal microbalances (QCMs), surface generated acoustic waves (SGAWs) and film bulk acoustic resonators (FBARs). However, this sensitivity improvement has not been completely matched in terms of limit of detection. The decrease on frequency stability due to the increase of the phase noise, particularly in oscillators, has made it impossible to increase the resolution. A new concept of sensor characterization at constant frequency has been recently proposed based on the phase/mass sensitivity equation: Δφ/Δm ≈ −1/mL, where mL is the liquid mass perturbed by the resonator. The validation of the new concept is presented in this article. An immunosensor application for the detection of a low molecular weight pollutant, the insecticide carbaryl, has been chosen as a validation model.

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Hearing What You Cannot See and Visualizing What You Hear: Interpreting Quartz Crystal Microbalance Data from Solvated Interfaces

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Authors: Ilya Reviakine, Diethelm Johannsmann and Ralf P. Richter

Journal: Analytical Chemistry, 2011

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