Real-time multianalyte biosensors based on interference-free multichannel monolithic quartz crystal microbalance.

Area of Science:

• Biosensing
• Materials Science
• Analytical Chemistry

Background:

• Quartz crystal microbalances (QCMs) are sensitive biosensors.
• Multichannel QCMs (MQCMs) offer multiplexed detection but suffer from inter-channel interference.
• Existing MQCM designs struggle with signal crosstalk, limiting their application.

Purpose of the Study:

• To develop an interference-free MQCM platform for enhanced bio-sensing.
• To suppress both mechanical and electrical coupling between QCM channels.
• To demonstrate the platform's capability for multi-analyte detection.

Main Methods:

• Fabrication of an MQCM with polydimethylsiloxane walls to prevent mode coupling.
• Design of extended flow channels to reduce electrical impedance coupling.
• Immobilization of antibodies (anti-IgG, anti-HSA) for specific analyte capture.
• Testing with single- and double-analyte solutions under continuous flow.

Main Results:

• Successfully suppressed thickness-shear vibration mode coupling and electrical coupling between QCM channels.
• Demonstrated interference-free operation with minimal cross-talk during liquid loading.
• Achieved specific and sensitive detection of IgG and HSA.
• Observed a linear frequency shift response with analyte concentration.

Conclusions:

• The developed MQCM platform provides real-time, label-free, and interference-free detection of multiple bio-analytes.
• This technology holds significant promise for advanced diagnostic and research applications.
• The design overcomes key limitations of previous MQCM systems, enabling robust multiplexed sensing.