Design and development of a portable low-cost QCM-based system for liquid biosensing

Abstract

Quartz crystal microbalance (QCM) is a versatile sensing platform that has gained increasing attention for its use in bioapplications due to its high sensitivity, real-time measurement capabilities, and label-free detection. This article presents a portable QCM system for liquid biosensing that uses a modified Hartley oscillator to drive 14 mm-diameter commercial QCM sensors. The system is designed to be low-cost, easy to use, and highly sensitive, making it ideal for various bioapplications. A new flow cell design to deliver samples to the surface of the sensor has been designed, fabricated, and tested. For portability and miniaturization purposes, a micropump-based pumping system is used in the current system. The system has a built-in temperature controller allowing for accurate frequency measurements. In addition, the system can be used in benchtop mode. The capability of the present system to be used in liquid biosensing is demonstrated through an experimental test for sensitivity to changes in the viscosity of glycerol samples. It was found to have a sensitivity of 263.51 Hz/mPa.s using a 10 MHz QCM sensor. Future work regarding potential applications was suggested. Graphical Abstract

Electric Field-Assisted Molecularly Imprinted Polymer-Modified QCM Sensor for Enhanced Detection of Immunoglobulin

“…Eq describes how the QCM’s frequency shift relates to the change in mass accumulated on its surface. ,, Δ f r stands for the frequency shift, while f 0 is the initial oscillating frequency, Δ m is the change in mass ( g ), A is the effective area (cm 2 ), ρ q is quartz density (g cm –3 ), and μ q stands for quartz shear modulus (g cm –1 s –2 ). It is worth mentioning that this equation is just valid for a thin rigid layer of mass change. , However, many studies in this field focused on fabricating a microfluidic setup that makes the commercial and user-friendly usage of MIP-modified QCM an arduous task. , In order to alleviate the use of MIP-modified QCM sensors, static measurements in the liquid phase were conducted as an alternative to the traditional ways. Eq replaces eq , where the viscosity and density of the Newtonian solution also play roles in the frequency shift. normalΔ f r = prefix− 2 f 0 2 normalΔ m A ρ q μ q normalΔ f r = prefix− f 0 3 / 2 ρ normall η normall π ρ normalq μ normalq …”

“… 24 , 33 However, many studies in this field focused on fabricating a microfluidic setup that makes the commercial and user-friendly usage of MIP-modified QCM an arduous task. 34 , 35 In order to alleviate the use of MIP-modified QCM sensors, static measurements in the liquid phase were conducted as an alternative to the traditional ways. Eq 2 replaces eq 1 , where the viscosity and density of the Newtonian solution also play roles in the frequency shift.…”

Design, Fabrication and Performance Analysis of a Portable, Antenna Analyzer Based, Quartz Crystal Microbalance Measuring System with Energy Dissipation

“…OpenQCM's NEXT is the only commercially available platform as of today that can measure resonance frequency and dissipation simultaneously, however it lacks the ability to take measurements in elevated temperatures and it does not come with a pump or PC or any other portable single board computer (SBC). There are also portable measurements systems in the literature [15][16][17][18]. Adel et.…”

“…'s study uses a frequency counter and heating and cooling air conditioning (AC) system for the flow cell although the AC system is only demonstrated to work between 19 o C and 29 o C. which is not suitable for isothermal amplification techniques. Moreover the system does not include a portable pump and a PC is required and most importantly the system does not measure dissipation factor but only the resonance frequency [15]. Beißner et.…”