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

Journal Article · Wed Jun 15 04:00:00 EDT 2011 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.3598340· OSTI ID:22062367

Montagut, Y J; Garcia, J V; Jimenez, Y; Arnau, A ^[1]; March, C; Montoya, A ^[2]

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1. Grupo de Fenomenos Ondulatorios, Departamento de Ingenieria Electronica, Universitat Politecnica de Valencia (Spain)
2. Instituto Interuniversitario de Investigacion en Bioingenieria y Tecnologia Orientada al Ser Humano, Universitat Politecnica de Valencia (Spain)

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.

• OSTI ID: 22062367
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 6 Vol. 82; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CONTAMINATION
CRYSTALS
FREQUENCY MODULATION
INSECTICIDES
LIQUIDS
MICROBALANCES
NOISE
OSCILLATORS
PHASE SHIFT
QUARTZ
RESOLUTION
SENSITIVITY
SENSORS
VALIDATION