Antibody immobilization techniques in mass sensitive immunosensor: enhanced sensitivity through limited mass load

Background: Biosensors are analytical devices that include a sample-delivery approach between a biological recognition element and a transducer required to convert the physicochemical change produced from the interaction of biological molecules-receptor interaction into signal. The immunosensor is a special type of biosensors that includes an antibody as a biorecognition element to detect analyte as antigens. In mass-sensitive sensors, antigen-antibody interactions can be specified by measuring the frequency change and most commonly knowns are surface acoustic wave, bulk acoustic wave, quartz crystal microbalance and microcantilevers. Methods: Different methods for antibody immobilization including functionalization of the transducer surface with specific groups have been reported for antibody immobilization. This stage affects the limit of detection and overall performance. In this review, perspectives on immobilization strategies of mass sensitive immunosensors according to transducer types will be presented. The choice of immobilization methods and their impact on performance in terms of capture molecule loading, orientation and signal improvement is will also be discussed. Results: One of the most critical point during configuration of the biorecognition layer is to improve the sensitivity. Therefore, we initially focused on comparisons of the antibody immobilization strategies in the biorecognition layer in terms of mass load level and high sensitivity. Conclusion: The lack of significant data on the mass accumulations up to the functionalization and antibody immobilization steps, which are the basis of immusensor production, has been identified. However, mass sensitive immunosensors have the potential to become more common and effective analytical devices for many application areas.

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Determination of Ammonia and Aliphatic Amines in Food by Ion Chromatography with Double-Cell Bulk Acoustic Wave Detection

Journal of AOAC International ◽

10.1093/jaoac/81.5.1099 ◽

1998 ◽

Vol 81 (5) ◽

pp. 1099-1103 ◽

Cited By ~ 2

Author(s):

Shouzhuo Yao ◽

Xiaorong Yang ◽

Hong Zhang ◽

Youtao Xie ◽

Wanzhi Wei

Keyword(s):

Acoustic Wave ◽

Mobile Phase ◽

Quartz Crystal ◽

High Sensitivity ◽

Aliphatic Amines ◽

Bulk Acoustic Wave ◽

Wave Detection ◽

Relative Standard ◽

Cured Meat

Abstract An ion chromatographic (IC) method with doublecell bulk acoustic wave (DCBAW) detection is described for determination of ammonia and low-molecular- mass aliphatic amines in food. A 9 MHz AT-cut quartz crystal is used as the resonator. This detection technique provides high sensitivity, good reproducibility, and wide work region. Its sensitivity is independent of background conductivity of the mobile phase in the range 10-2700 μS. Detection limits (peak = 3 δ) for NH4+, CH3NH3+ (CH3)2NH2+and (CH3)3NH+ were 0.02, 0.05, 0.13, and 0.6 μg/mL, respectively. Relative standard deviations for NH4+, CH3NH3+, (CH3)2NH2+, and (CH3)3NH+ were 0.7,1.0, 0.8, and 1.2%, respectively. For IC analysis, the analytical column is a Shim-pack IC-C1 column and the mobile phase is 2.0 mmol/L nitric acid solution at a flow rate of 1.5 mL/min. Detection with DCBAW was compared with series bulk acoustic wave and conventional conductivity. The method was applied to analyses of egg, fish, and cured meat

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Regenerable ZnO/GaAs Bulk Acoustic Wave Biosensor for Detection of Escherichia coli in “Complex” Biological Medium

Biosensors ◽

10.3390/bios11050145 ◽

2021 ◽

Vol 11 (5) ◽

pp. 145

Author(s):

Juliana Chawich ◽

Walid M. Hassen ◽

Céline Elie-Caille ◽

Thérèse Leblois ◽

Jan J. Dubowski

Keyword(s):

Escherichia Coli ◽

Acoustic Wave ◽

Limit Of Detection ◽

Bulk Acoustic Wave ◽

Back Surface ◽

Label Free ◽

Lateral Field ◽

E Coli ◽

Assembled Monolayers ◽

Field Excitation

A regenerable bulk acoustic wave (BAW) biosensor is developed for the rapid, label-free and selective detection of Escherichia coli in liquid media. The geometry of the biosensor consists of a GaAs membrane coated with a thin film of piezoelectric ZnO on its top surface. A pair of electrodes deposited on the ZnO film allows the generation of BAWs by lateral field excitation. The back surface of the membrane is functionalized with alkanethiol self-assembled monolayers and antibodies against E. coli. The antibody immobilization was investigated as a function of the concentration of antibody suspensions, their pH and incubation time, designed to optimize the immunocapture of bacteria. The performance of the biosensor was evaluated by detection tests in different environments for bacterial suspensions ranging between 103 and 108 CFU/mL. A linear dependence between the frequency response and the logarithm of E. coli concentration was observed for suspensions ranging between 103 and 107 CFU/mL, with the limit of detection of the biosensor estimated at 103 CFU/mL. The 5-fold regeneration and excellent selectivity towards E. coli detected at 104 CFU/mL in a suspension tinted with Bacillus subtilis at 106 CFU/mL illustrate the biosensor potential for the attractive operation in complex biological media.

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Instant Mercury Ion Detection in Industrial Waste Water with a Microchip Using Extended Gate Field-Effect Transistors and a Portable Device

Sensors ◽

10.3390/s19092209 ◽

2019 ◽

Vol 19 (9) ◽

pp. 2209 ◽

Cited By ~ 1

Author(s):

Revathi Sukesan ◽

Yi-Ting Chen ◽

Suman Shahim ◽

Shin-Li Wang ◽

Indu Sarangadharan ◽

...

Keyword(s):

Detection Limit ◽

Inductively Coupled Plasma ◽

Field Effect ◽

Field Effect Transistors ◽

Limit Of Detection ◽

High Sensitivity ◽

Water Quality Monitoring ◽

Mercury Ion ◽

Enhanced Sensitivity ◽

High Concentrations

Mercury ion selective membrane (Hg-ISM) coated extended gate Field Effect transistors (ISM-FET) were used to manifest a novel methodology for ion-selective sensors based on FET’s, creating ultra-high sensitivity (−36 mV/log [Hg2+]) and outweighing ideal Nernst sensitivity limit (−29.58 mV/log [Hg2+]) for mercury ion. This highly enhanced sensitivity compared with the ion-selective electrode (ISE) (10−7 M) has reduced the limit of detection (10−13 M) of Hg2+ concentration’s magnitude to considerable orders irrespective of the pH of the test solution. Systematical investigation was carried out by modulating sensor design and bias voltage, revealing that higher sensitivity and a lower detection limit can be attained in an adequately stronger electric field. Our sensor has a limit of detection of 10−13 M which is two orders lower than Inductively Coupled Plasma Mass Spectrometry (ICP-MS), having a limit of detection of 10−11 M. The sensitivity and detection limit do not have axiomatic changes under the presence of high concentrations of interfering ions. The technology offers economic and consumer friendly water quality monitoring options intended for homes, offices and industries.

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