Sensitive label-free immunoglobulin G detection using a MEMS quartz crystal microbalance biosensor with a 125 MHz wireless quartz resonator

We present a wireless quartz crystal microbalance (QCM) biosensor fabricated using MEMS technology. The MEMS QCM biosensor contains a 125 MHz AT-cut quartz resonator embedded in the microchannel. Because of the compact design, the MEMS QCM biosensor is suitable for mass production and device miniaturization. We performed immunoglobulin G (IgG) detection measurements with different concentrations of IgG. The detection limit was 1 ng ml-1 or less, which is superior to that of the gold-standard surface plasma resonance method. Furthermore, we studied the binding affinity between protein A and IgG by studying the frequency response of the QCM biosensor. We found good agreement with reported values. Therefore, the presented MEMS QCM biosensor has the advantages of compactness, low cost, low power consumption, high sensitivity, and reliability.This is the Accepted Manuscript version of an article accepted for publication in Japanese Journal of Applied Physics. IOP Publishing Ltd are not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at https://doi.org/10.35848/1347-4065/abea50

Mass-Fabrication Scheme of Highly Sensitive Wireless Electrodeless MEMS QCM Biosensor with Antennas on Inner Walls of Microchannel

Zhou L., Kato F., Iijima M., et al. Mass-Fabrication Scheme of Highly Sensitive Wireless Electrodeless MEMS QCM Biosensor with Antennas on Inner Walls of Microchannel. Analytical Chemistry 95, 5507 (2023); https://doi.org/10.1021/acs.analchem.3c00139.Quartz-crystal-microbalance (QCM) biosensor is a typical label-free biosensor, and its sensitivity can be greatly improved by removing electrodes and wires that would be otherwise attached to the surfaces of the quartz resonator. The wireless-electrodeless QCM biosensor was then developed using a microelectro-mechanical systems (MEMS) process, although challenges remain in the sensitivity, the coupling efficiency, and the miniaturization (or mass production). In this study, we establish a MEMS process to obtain a large number of identical ultrasensitive and highly efficient sensor chips with dimensions of 6 mm square. The fundamental shear resonance frequency of the thinned AT-cut quartz resonator packaged in the microchannel exceeds 160 MHz, which is excited by antennas deposited on inner walls of the microchannel, significantly improving the electro-mechanical coupling efficiency in the wireless operation. The high sensitivity of the developed MEMS QCM biosensors is confirmed by the immunoglobulin G (IgG) detection using protein A and ZZ-tag displaying a bionanocapsule (ZZ-BNC), where we find that the ZZ-BNC can provide more effective binding sites and higher affinity to the target molecules, indicating a further enhancement in the sensitivity of the MEMS QCM biosensor. We then perform the label-free C-reactive protein (CRP) detection using the ZZ-BNC-functionalized MEMS QCM biosensor, which achieves a detection limit of 1 ng mL-1 or less even with direct detection

Ultrahigh-frequency, wireless mems qcm biosensor for direct, label-free detection of biomarkers in a large amount of contaminants

Label-free biosensors, including conventional quartz-crystal-microbalance (QCM) biosensors, are seriously affected by nonspecific adsorption of contaminants involved in analyte solution, and it is exceptionally difficult to extract the sensor responses caused only by the targets. In this study, we reveal that this difficulty can be overcome with an ultrahigh-frequency, wireless QCM biosensor. The sensitivity of a QCM biosensor dramatically improves when the quartz resonator is thinned, which also makes the resonance frequency higher, causing high-speed surface movement. Contaminants weakly (nonspecifically) interact with the quartz surface, but they fail to follow the fast surface movement and cannot be detected as the loaded mass. The targets are, however, tightly captured by the receptor proteins immobilized on the surface, and they can move with the surface, contributing to the loaded mass and decreasing the resonant frequency. We have developed a MEMS QCM biosensor in which an AT-cut quartz resonator, 26 μm thick, is packaged without fixing, and we demonstrate this phenomenon by comparing the frequency changes of the fundamental (∼64 MHz) and ninth (∼576 MHz) modes. At ultrahigh-frequency operation with the ninth mode, the sensor response is independent of the amount of impurity proteins, and the binding affinity is unchanged. We then applied this method to the label-free and sandwich-free, direct detection of C-reactive protein (CRP) in serum and confirmed its applicability.Kentaro Noi, Arihiro Iwata, Fumihito Kato, and Hirotsugu Ogi. Ultrahigh-frequency, wireless mems qcm biosensor for direct, label-free detection of biomarkers in a large amount of contaminants. Analytical Chemistry, 2019, 91(15), 9398-9402. ©2019 American Chemical Society. https://doi.org/10.1021/acs.analchem.9b01414

Viscoelasticity Response during Fibrillation of Amyloid β Peptides on a Quartz-Crystal-Microbalance Biosensor

Unlike previous in vitro measurements where Amyloid β (Aβ) aggregation was studied in bulk solutions, we detect the structure change of the Aβ aggregate on the surface of a wireless quartz-crystal-microbalance biosensor, which resembles more closely the aggregation process on the cell membrane. Using a 58 MHz quartz crystal, we monitored changes in the viscoelastic properties of the aggregate formed on the quartz surface from monomers to oligomers and then to fibrils, involving up to the 7th overtone mode (406 MHz). With atomic-force microscopy observations, we found a significant stiffness increase as well as thinning of the protein layer during the structure change from oligomer to fibrils at 20 h, which indicates that the stiffness of the fibril is much higher. Viscoelasticity can provide a significant index of fibrillation and can be useful for evaluating inhibitory medicines in drug development.Yen-Ting Lai, Hirotsugu Ogi, Kentaro Noi, and Fumihito Kato. Viscoelasticity Response during Fibrillation of Amyloid β Peptides on a Quartz-Crystal-Microbalance Biosensor. Langmuir, 2018, 34(19), 5474-5479. ©2018 American Chemical Society. https://doi.org/10.1021/acs.langmuir.8b00639

浸漬ワクチンによる滑走細菌症の防除に関する研究

学位の種類：農学　　学位授与年月日：平成19年3月22日　　主査：熊井, 英水 教授　　報告番号：甲第821号　　学内授与番号：農第103号　　NDL書誌ID： 000008809062本文URL:http://kurepo.clib.kindai.ac.jp/modules/xoonips/detail.php?id=AN00379737-20130331-000

Mechanism of affinity-enhanced protein adsorption on bio-nanocapsules studied by viscoelasticity measurement with wireless QCM biosensor

Recent advances in functionalized bio-nanocapsules (BNCs) have allowed a significant sensitivity enhancement in label-free biosensors. It is suggested that sensitivity amplification is caused by the higher binding affinity of BNCs to target antibodies. We here study the high-affinity interaction mechanism between BNCs and antibodies with wireless high-frequency QCM biosensors. We first confirmed the higher affinity between BNCs and human immunoglobulin G. We then found that the number of binding sites for the target antibody significantly increases by immobilizing BNC molecules on the sensor surface. We finally studied changes in viscoelasticity near the sensor surface using a MEMS wireless QCM biosensor using up to the ninth overtone (522 MHz). The inversely determined effective shear modulus on BNCs was found to be significantly lower than that on a standard surface on which the receptor molecules were immobilized. We have thus clarified that this surface flexibility achieves high affinity with target antibodies.This is the Accepted Manuscript version of an article accepted for publication in Japanese Journal of Applied Physics. IOP Publishing Ltd are not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at https://doi.org/10.35848/1347-4065/ab78e1

Viscoelasticity evolution in protein layers during binding reactions evaluated using high-frequency wireless and electrodeless quartz crystal microbalance biosensor without dissipation

In this study, we demonstrate the effectiveness of a resonance acoustic microbalance with a naked embedded quartz (RAMNE-Q) biosensor for evaluating viscoelastic property changes in thin protein layers during protein deposition reactions without dissipation measurement. Quartz crystal microbalance (QCM) biosensors have conventionally been adopted for the viscoelasticity evaluation of adsorbed protein layers by measuring dissipation as well as resonance frequency. However, dissipation, or the vibrational energy loss, is easily affected by many factors and is rarely measured with sufficiently high accuracy. To evaluate viscoelasticity only from a reliable frequency response, one needs to perform an ultrahighfrequency measurement, which is here achieved using the RAMNE-Q biosensor. Simultaneous frequency measurement is performed for fundamental and overtone modes up to 406MHz of a 58MHz RAMNE-Q biosensor during various binding reactions, and evolutions of viscosity, shear modulus, and thickness of adsorbed protein layers are inversely evaluated. A marked difference is observed in the viscosity evolution between specific and nonspecific binding reactions. Furthermore, the reversed frequency response appears, which indicates the modification of the protein structure into a rigid structure.Tomohiro Shagawa, Hiroomi Torii, Fumihito Kato, Hirotsugu Ogi and Masahiko Hirao. Viscoelasticity evolution in protein layers during binding reactions evaluated using high-frequency wireless and electrodeless quartz crystal microbalance biosensor without dissipation. Japanese Journal of Applied Physics, 2015, 54(9), 096601. https://doi.org/10.7567/JJAP.54.096601

Relationship between viscosity change and specificity in protein binding reaction studied by high-frequency wireless and electrodeless MEMS biosensor

This study proposes a methodology for evaluating specific binding behavior between proteins using a resonance acoustic microbalance with a naked-embedded quartz (RAMNE-Q) biosensor. We simultaneously measured the frequency responses of fundamental (58 MHz) and third-order (174 MHz) modes during multi step injections of proteins and deduced the thickness and viscosity evolutions of the protein layer. The viscosity increases with the progress of the binding reaction in nonspecific binding, but it markedly decreases in specific-binding cases. Thus, the high-frequency RAMNE-Q biosensor can be a powerful tool for evaluating specificity between proteins without measuring dissipation.Tomohiro Shagawa, Hiroomi Torii, Fumihito Kato, Hirotsugu Ogi and Masahiko Hirao. Relationship between viscosity change and specificity in protein binding reaction studied by high-frequency wireless and electrodeless MEMS biosensor. Japanese Journal of Applied Physics, 2015, 54(6), 068001. https://doi.org/10.7567/JJAP.54.068001