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1 – 10 of 74Yijun Teh, Asral Bahari Jambek and Uda Hashim
This paper aims to discuss a nanoscale biosensor and its signal analysis algorithms.
Abstract
Purpose
This paper aims to discuss a nanoscale biosensor and its signal analysis algorithms.
Design/methodology/approach
In this work, five nanoscale biosensors are reviewed, namely, silicon nanowire field-effect-transistor biosensors, polysilicon nanogap capacitive biosensors, nanotube amperometric biosensors, gold nanoparticle-based electrochemical biosensors and quantum dot-based electrochemical biosensors.
Findings
Each biosensor produces a different output signal depending on its electrical characteristics. Five signal analysers are studied, with most of the existing signal analyser analyses based on the amplitude of the signal. Based on the analysis, auto-threshold peak detection is proposed for further work.
Originality/value
Suitability of the signal processing algorithm to be applied to nano-biosensors was reported.
Details
Keywords
Helmi Wasoh, Lee Yook Hengb, Fatimah Abu Bakar, Rahman Wagiran, Abu Bakar Salleh, Nor Azah Yusof, Norhisam Misrond and Fatin Hazimah Abdul Rahmane
The purpose of this paper is to describe a capacitive biosensor device consisting of an enzyme electrode and a simple detector which has been developed for histamine measurement.
Abstract
Purpose
The purpose of this paper is to describe a capacitive biosensor device consisting of an enzyme electrode and a simple detector which has been developed for histamine measurement.
Design/methodology/approach
In this analysis, degradation of histamine through enzymatic reaction produces signal that is monitored using a simple detector equipped with “astable” multivibrator operation circuit (in capacitor‐resistor circuit).
Findings
Different frequency (f) readings have been obtained for glucose, alcohol and histamine in different concentration levels, showing the ability of this simple device system to measure their dielectric constant (k) as formulated by the equation f=(1.44d)/ [kA (R1+2R2)]. The analysis using smaller electrode gap (d) produces higher value of f, indicating that d, is directly proportional to f. For histamine, by using immobilized enzyme electrode, the results show that the change of dielectric properties during the 300‐second reaction period could also be monitored. A linear relationship is obtained between concentration and frequency from 50 to 200 ppm.
Practical implications
Based on this result, an enzyme electrode and “astable” operation circuits have the potential to be used in the development of a simple capacitive biosensor device.
Originality/value
The paper is an outcome of experimental work carried out to observe capacitive sensing behavior using an immobilized enzyme, to measure biological samples, especially histamine.
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Sharipah Nadzirah and Uda Hashim
The purpose of this study is to fabricate a transducer-based TiO2 interdigitated microelectrodes with various gap sizes. The most stable electrical properties have been selected…
Abstract
Purpose
The purpose of this study is to fabricate a transducer-based TiO2 interdigitated microelectrodes with various gap sizes. The most stable electrical properties have been selected for Escherichia. coli O157:H7 DNA detection.
Design/methodology/approach
Sol-gel was used to synthesize TiO2 nanoparticles. Lift-off photolithography process was used for fabrication of interdigitated electrodes (IDEs) and dry-state DNA detection was done using a Picoammeter.
Findings
TiO2 nanoparticles IDEs with 16-um gap size is able to detect DNA of E. coli in a dry state.
Originality/value
This paper describes IDEs for dry-state detection of E. coli O157:H7 DNA. The technique presented in this paper ensures the high uniformity of nanoparticle deposition on the finger electrode.
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Anindya Bose and Sarthak Sengupta
A bio-sensor has been developed in this study for the purpose of point-of-care diagnostics. Point-of-care-diagnostic is a type of diagnosis where the diagnostic centre, i.e. the…
Abstract
Purpose
A bio-sensor has been developed in this study for the purpose of point-of-care diagnostics. Point-of-care-diagnostic is a type of diagnosis where the diagnostic centre, i.e. the diagnosis kit is made available at the location of the patient when the patient needs immediate action. In this process of diagnosis a compact, portable, integrated kit must be available which can diagnose the disease of the patient by testing various analytes.
Design/methodology/approach
Using a fully experimental methodology, a blood glucose sensor is made by conducting carbon interdigitated electrode (IDE) on a flexible substrate. IDEs are used to increase the effective capacitance of the structure, as well as the effective electroactive area of the sensor. Interdigitated structure permits two-electrode sticks with “each other” and “infuse” together. As a consequence, the distance between electrodes can be tuned to a much smaller value than traditional thin-film architectures. Narrowing the distance between electrodes allows for fast ion diffusion that offers better rate capability and efficiency in power density. The fabricated device exhibits a remarkable value of sensitivity in the order of 2.741 µA mM-1 cm−2.
Findings
A highly sensitive, portable and inexpensive blood glucose sensor has been developed in this context.
Originality/value
This research study can be a scope for future research in the field of bio-sensors.
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Keywords
Qian Yee Ang and Siew Chun Low
Molecularly imprinted polymers (MIPs) have aroused focus in medicinal chemistry in recent decades, especially for biomedical applications. Considering the exceptional abilities to…
Abstract
Purpose
Molecularly imprinted polymers (MIPs) have aroused focus in medicinal chemistry in recent decades, especially for biomedical applications. Considering the exceptional abilities to immobilize any guest of medical interest (antibodies, enzymes, etc.), MIPs is attractive to substantial research efforts in complementing the quest of biomimetic recognition systems. This study aims to review the key-concepts of molecular imprinting, particularly emphasizes on the conformational adaptability of MIPs beyond the usual description of molecular recognition. The optimal morphological integrity was also outlined in this review to acknowledge the successful sensing activities by MIPs.
Design/methodology/approach
This review highlighted the fundamental mechanisms and underlying challenges of MIPs from the preparation stage to sensor applications. The progress of electrochemical and optical sensing using molecularly imprinted assays has also been furnished, with the evolvement of molecular imprinting as a research hotspot.
Findings
The lack of standard synthesis protocol has brought about an intriguing open question in the selection of building blocks that are biocompatible to the imprint species of medical interest. Thus, in this paper, the shortcomings associated with the applications of MIPs in electrochemical and optical sensing were addressed using the existing literature besides pointing out possible solutions. Future perspectives in the vast development of MIPs also been postulated in this paper.
Originality/value
The present review intends to furnish the underlying mechanisms of MIPs in biomedical diagnostics, with the aim in electrochemical and optical sensing while hypothesizing on future possibilities.
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Xingya Wang and Guangchang Pang
This paper aims to provide a detailed review of weak interaction biosensors and several common biosensor methods for magnifying signals, as well as judiciously guide readers…
Abstract
Purpose
This paper aims to provide a detailed review of weak interaction biosensors and several common biosensor methods for magnifying signals, as well as judiciously guide readers through selecting an appropriate detecting system and signal amplification method according to their research and application purpose.
Design/methodology/approach
This paper classifies the weak interactions between biomolecules, summarizes the common signal amplification methods used in biosensor design and compares the performance of different kinds of biosensors. It highlights a potential electrochemical signal amplification method: the G protein signaling cascade amplification system.
Findings
Developed biosensors which, based on various principles, have their own strengths and weaknesses have met the basic detection requirements for weak interaction between biomolecules: the selectivity, sensitivity and detection limit of biosensors have been consistently improving with the use of new signal amplification methods. However, most of the weak interaction biosensors stop at the research stage; there are only a minority realization of final commercial application.
Originality/value
This paper evaluates the status of research and application of weak interaction biosensors systematically. The G protein signaling cascade amplification system proposal offers a new avenue for the research and development of electrochemical biosensors.
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Dinesh Ramkrushna Rotake, Anand D. Darji and Nitin S. Kale
This paper aims to propose a new microfluidic portable experimental platform for quick detection of heavy metal ions (HMIs) in picomolar range. The experimental setup uses a…
Abstract
Purpose
This paper aims to propose a new microfluidic portable experimental platform for quick detection of heavy metal ions (HMIs) in picomolar range. The experimental setup uses a microfabricated piezoresistive sensor (MPS) array of eight cantilevers with ion-selective self-assembled monolayer's (SAM).
Design/methodology/approach
Most of the components used in this experimental setup are battery operated and, hence, portable to perform the on-field experiments. HMIs (antigen) and thiol-based SAM (antibody) interaction start bending the microcantilever. This results in a change of resistance, which is directly proportional to the surface stress produced due to the mass of targeted HMIs. The authors have used Cysteamine and 4-Mercaptobenzoic acid as a thiol for creating SAM to test the sensitivity and identify the suitable thiol. Some of the cantilevers are blocked using acetyl chloride to use as a reference for error detection.
Findings
The portable experimental platform achieves very small detection time of 10-25 min with a lower limit of detection (LOD) 0.762 ng (6.05 pM) for SAM of Cysteamine and 4-Mercaptobenzoic acid to detect Mn2+ ions. This technique has excellent potential and capability to selectively detect Hg2+ ions as low as 2.43 pM/mL using SAM of Homocysteine (Hcys)-Pyridinedicarboxylic acid (PDCA).
Research limitations/implications
As microcantilever is very thin and fragile, it is challenging to apply a surface coating to have selective detection using Nanadispenser. Some of the cantilevers get broken during this process.
Originality/value
The excessive use and commercialization of NPs are quickly expanding their toxic impact on health and the environment. Also, LOD is limited to nanomolar range. The proposed method used the combination of thin-film, NPs, and MEMS-based technology to overcome the limitation of NPs-based technique and have picomolar range of HMIs detection.
Details
Keywords
Amin Eidi, Mousa Shamsi and Habib Badri Ghavifekr
In this work, the sensing and actuating elements are designed with interdigitated capacitors away from the sensitive element on which the droplet is placed. This pattern helps to…
Abstract
Purpose
In this work, the sensing and actuating elements are designed with interdigitated capacitors away from the sensitive element on which the droplet is placed. This pattern helps to prevent interference of electrical elements with the droplet. Choosing shear resonance mode at this proposed structure minimizes the damping effect of droplet touch by the resonator structure. The glass-based standard fabrication method of the proposed biosensor is presented exactly.
Design/methodology/approach
Mechanical resonator sensors are extremely limited because of the high damping factor and the high electrical conductivity in the aqueous environment. In this work, a molecule detector biosensor is proposed for droplet analysis, which is possible to fabricate using micro-electro-mechanical systems (MEMS) technology. By electromechanical coupling of resonators as a mechanical resonator structure, a standing mechanical wave is formed at this structure by electrostatic actuating elements.
Findings
In this paper, a mechanical resonator structure as a biosensor is proposed for micro-droplet analysis that can be fabricated by MEMS technology. It is designed at a lower cost fabrication method using electrostatic technology and interdigitated capacitors. The response of the biosensor displacement frequency at the resonance frequency of the desired mode is reasonable for measuring the capacitive changes of its output. The mass sensitivity of the proposed biosensor is in the range of 1 ng, and it has a large sensitive area for capturing target molecules.
Originality/value
To evaluate the quality of the proposed design, the stimulated analysis is conducted by COMSOL and results are presented.
Details
Keywords
Bjorn John Stephen, Surabhi Suchanti, Devendra Jain, Harshdeep Dhaliwal, Vikram Sharma, Ramandeep Kaur, Rajeev Mishra and Abhijeet Singh
Neglected tropical diseases (NTDs) are a set of infectious diseases that primarily affect low-income countries situated near the equator. Effective diagnostic tools hold the key…
Abstract
Purpose
Neglected tropical diseases (NTDs) are a set of infectious diseases that primarily affect low-income countries situated near the equator. Effective diagnostic tools hold the key to stemming the spread of these infectious diseases. However, specificity is a major concern associated with current diagnostic protocols. In this regard, electrochemical deoxyribonucleic acid (DNA) biosensors could play a crucial role, as highlighted by renewed interest in their research. The purpose of this study was to highlight the current scenario for the design and development of biosensors for the detection of NTDs related pathogens. This review highlights the different types of factors involved and the modifications used to enhance sensor properties.
Design/methodology/approach
The authors discuss the potential of electrochemical DNA biosensors as efficient, affordable diagnostic tools for the detection of pathogens associated with NTDs by reviewing available literature. This study discusses the biosensor components, mainly the probe selection and type of electrodes used, and their potential to improve the overall design of the biosensor. Further, this study analyses the different nanomaterials used in NTD-based electrochemical DNA biosensors and discusses how their incorporation could improve the overall sensitivity and specificity of the biosensor design. Finally, this study examines the impact such techniques could have in the future on mass screening of NTDs.
Findings
The findings provide an in-depth analysis of electrochemical DNA biosensors for the detection of pathogens associated with NTDs.
Originality/value
This review provides an update on the different types and modifications of DNA biosensors that have been designed for the diagnosis of NTD-related pathogens.
Details
Keywords
Sajad Pirsa and Fahime Purghorbani
In this study, an attempt has been made to collect the research that has been done on the construction and design of the H2O2 sensor. So far, many efforts have been made to…
Abstract
Purpose
In this study, an attempt has been made to collect the research that has been done on the construction and design of the H2O2 sensor. So far, many efforts have been made to quickly and sensitively determine H2O2 concentration based on different analytical principles. In this study, the importance of H2O2, its applications in various industries, especially the food industry, and the importance of measuring it with different techniques, especially portable sensors and on-site analysis, have been investigated and studied.
Design/methodology/approach
Hydrogen peroxide (H2O2) is a very simple molecule in nature, but due to its strong oxidizing and reducing properties, it has been widely used in the pharmaceutical, medical, environmental, mining, textile, paper, food production and chemical industries. Sensitive, rapid and continuous detection of H2O2 is of great importance in many systems for product quality control, health care, medical diagnostics, food safety and environmental protection.
Findings
Various methods have been developed and applied for the analysis of H2O2, such as fluorescence, colorimetry and electrochemistry, among them, the electrochemical technique due to its advantages in simple instrumentation, easy miniaturization, sensitivity and selectivity.
Originality/value
Monitoring the H2O2 concentration level is of practical importance for academic and industrial purposes. Edible oils are prone to oxidation during processing and storage, which may adversely affect oil quality and human health. Determination of peroxide value (PV) of edible oils is essential because PV is one of the most common quality parameters for monitoring lipid oxidation and oil quality control. The development of cheap, simple, fast, sensitive and selective H2O2 sensors is essential.
Details