Biosensing on the centrifugal microfluidic lab-on-a-Disc platform

Lab-on-a-Disc (LoaD) biosensors are increasingly a promising solution for many biosensing applications. In the search for a perfect match between point-of-care (PoC) microfluidic devices and biosensors, the LoaD platform has the potential to be reliable, sensitive, low-cost, and easy-to-use. The present global pandemic draws attention to the importance of rapid sample-to-answer PoC devices for minimising manual intervention and sample manipulation, thus increasing the safety of the health professional while minimising the chances of sample contamination. A biosensor is defined by its ability to measure an analyte by converting a biological binding event to tangible analytical data. With evolving manufacturing processes for both LoaDs and biosensors, it is becoming more feasible to embed biosensors within the platform and/or to pair the microfluidic cartridges with low-cost detection systems. This review considers the basics of the centrifugal microfluidics and describes recent developments in common biosensing methods and novel technologies for fluidic control and automation. Finally, an overview of current devices on the market is provided. This review will guide scientists who want to initiate research in LoaD PoC devices as well as providing valuable reference material to researchers active in the field

RECENT TRENDS IN DENGUE DETECTION METHODS USING BIOSENSORS

ABSTRACT: Dengue illness is an infectious tropical disease, transmitted by Aedes mosquitos, that poses a serious health threat to the tropical world. This disease causes widespread infection worldwide, with about 50 million cases of dengue occurring per annum out of which 500,000 recorded cases of dengue hemorrhagic fever and 22,000 deaths.  Currently, there are no effective vaccines available to prevent the spread of the infection. Accurate and rapid laboratory diagnostic tests are required for early detection to reduce patient mortality rate. In this paper,  common laboratory diagnosis methods for detecting dengue virus infection are discussed. Currently, virus isolation, RT-PCR and serology methods provide the most direct and accurate response for detection of dengue. However, these methods require tedious steps, expensive requirements and expert staffs. Recent research have proposed the usage of biosensors as an alternative new technology for detection of dengue. In this work, various types of biosensors such as electrochemical, piezoelectric, and optical biosensor have been described and compared to evaluate their effectiveness in dengue detection.  It is observed that the optical biosensor offers the best detection due to its high sensitivity as compared to others, although it is popularly known as an expensive method. Alternatively, the use of electrochemical and piezoelectric biosensors (QCM) is highly recommended for detection of dengue due to their ease-of-use, low cost, low reagent consumption, disposability, and minimal sample preparation. These approaches have the potential to improve the rate of survival, particularly in resource-limited countries. ABSTRAK: Virus denggi adalah penyakit berjangkit tropika bawaan nyamuk Aedes yang menimbulkan ancaman serius kepada kesihatan global. Penyakit ini menyebabkan jangkitan yang meluas di seluruh dunia, dengan kira-kira 50 juta kes denggi yang berlaku setiap tahun di mana 500,000 kes demam denggi berdarah dan 22,000 kematian direkodkan. Buat masa ini, tiada vaksin yang berkesan untuk mencegah penyebaran jangkitan ini. Ujian diagnostik makmal yang cepat dan tepat diperlukan untuk pengesanan denggi awal untuk mengurangkan kadar kematian pesakit. Dalam artikel ini, kaedah diagnosis makmal yang biasa dilakukan untuk mengesahkan jangkitan virus denggi akan dibincangkan. Pada masa kini, kaedah pengasingan virus, RT-PCR dan serologi adalah tindak balas yang paling cepat dan tepat untuk mengesan denggi. Walau bagaimanapun, kaedah-kaedah ini memerlukan langkah-langkah yang melecehkan, kos penyelenggaraan yang tinggi dan kakitangan  yang terlatih.  Penyelidikan terkini telah mencadangkan penggunaan biosensor sebagai teknologi baru alternatif untuk mengesan denggi.  Dalam artikel  ini juga pelbagai jenis biosensor seperti biosensor elektrokimia, piezoelektrik, dan biosensor optik telah dijelaskan dan dibandingkan untuk menilai keberkesanannya dalam pengesanan denggi. Difahamkan bahawa biosensor optik menawarkan pengesanan terbaik kerana kepekaannya yang tinggi berbanding dengan yang lain, walaupun ia dikenali sebagai kaedah berkos tinggi. Sebaliknya, biosensor elektrokimia dan piezoelektrik (QCM) sangat disyorkan untuk mengesan denggi kerana ia mudah digunakan, berkos rendah, penggunaan bahan uji yang terhad, boleh dipakai buang, dan mempunyai penyediaan sampel yang minima. Pendekatan-pendekatan ini berpotensi untuk meningkatkan kadar kemandirian di kawasan-kawasan sumber terhad

New Tools for Dengue Diagnostics

Dengue caused by four antigenically distinct serotype remains a serious health concern around the world, particularly in the tropical areas. Clinical signs and symptoms of this disease are indistinguishable from other infectious disease; therefore, laboratory diagnosis is very crucial for confirming the disease that will be useful for the patient’s management. In laboratory, dengue can be confirmed using cell culture, RNA detection, and serological detection based on ELISA and immunochromatographic test. However, each of these methods has certain practical limitations. Therefore, researchers from all over the world have been working to address these limitations. In this chapter, we will highlight the current research toward the development of novel point-of-care test for the diagnosis of dengue in acute and convalescent phase

Advances in Microfluidics Technology for Diagnostics and Detection

Microfluidics and lab-on-a-chip have, in recent years, come to the forefront in diagnostics and detection. At point-of-care, in the emergency room, and at the hospital bed or GP clinic, lab-on-a-chip offers the potential to rapidly detect time-critical and life-threatening diseases such as sepsis and bacterial meningitis. Furthermore, portable and user-friendly diagnostic platforms can enable disease diagnostics and detection in resource-poor settings where centralised laboratory facilities may not be available. At point-of-use, microfluidics and lab-on-chip can be applied in the field to rapidly identify plant pathogens, thus reducing the need for damaging broad spectrum pesticides while also reducing food losses. Microfluidics can also be applied to the continuous monitoring of water quality and can support policy-makers and protection agencies in protecting the environment. Perhaps most excitingly, microfluidics also offers the potential to enable entirely new diagnostic tests that cannot be implemented using conventional laboratory tools. Examples of microfluidics at the frontier of new medical diagnostic tests include early detection of cancers through circulating tumour cells (CTCs) and highly sensitive genetic tests using droplet-based digital PCR.This Special Issue on “Advances in Microfluidics Technology for Diagnostics and Detection” aims to gather outstanding research and to carry out comprehensive coverage of all aspects related to microfluidics in diagnostics and detection

Microfluidic Systems for Cancer Diagnostics

Cancer is the second leading cause of death in noncommunicable diseases coming right after cardiovascular diseases. Early diagnosis is a key for improving survival expectancy and treatment outcomes as cancer in early stage is more responsive to treatment. Currently, center of diseases control and prevention (CDC) recommend regular screening for cervical, breast and colorectal cancers. Although other screening procedures are available for prostate, pancreatic, thyroid and ovarian cancer, they did not prove to be effective in reducing mortality rates of these cancers. Adaption of prostate specific antigen (PSA) screening test for prostate cancer has not been related to improved survival rates instead it resulted in what has been known as “prostate cancer epidemic” due to overdiagnosis and overtreatment of prostate cancer. The dilemma of current cancer diagnostic techniques results from the trade-off between specificity and sensitivity of the cancer screening. Specific cancer screening strategies that depend on either imaging or histopathological examination are not sensitive enough and miss latent or asymptomatic cancers. While sensitive techniques that depend on biomarker screening in biofluids like PSA test are not specific enough for accurate decision. In addition, most of these techniques are time consuming, expensive and require centralized laboratories with highly trained technicians. These criteria limit the availability of cancer screening technique to developed countries with well-established healthcare systems and limit their application in areas with limited resources. The goal of this thesis is to develop and test techniques with promising specificity and sensitivity for screening and staging of different types of cancers. Several approaches have been studied to develop point-of-care (POC) sensors for prostate, head and neck cancers that are of low cost, utilizes low sample volumes, automated or semiautomated and can be utilized in remote areas with limited resources. 3D printing was used to prototype and mass produce microfluidic chips and adaptors with better fluid handling characteristics and much lower cost than traditional microfluidic systems. Panels of selected biomarker proteins were multiplexed on the same microfluidic chip to improve assay septicity while maintaining ultralow sensitivities

Recent Advances of Fluid Manipulation Technologies in Microfluidic Paper-Based Analytical Devices (μPADs) toward Multi-Step Assays

Microfluidic paper-based analytical devices (μPADs) have been suggested as alternatives for developing countries with suboptimal medical conditions because of their low diagnostic cost, high portability, and disposable characteristics. Recently, paper-based diagnostic devices enabling multi-step assays have been drawing attention, as they allow complicated tests, such as enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR), which were previously only conducted in the laboratory, to be performed on-site. In addition, user convenience and price of paper-based diagnostic devices are other competitive points over other point-of-care testing (POCT) devices, which are more critical in developing countries. Fluid manipulation technologies in paper play a key role in realizing multi-step assays via μPADs, and the expansion of biochemical applications will provide developing countries with more medical benefits. Therefore, we herein aimed to investigate recent fluid manipulation technologies utilized in paper-based devices and to introduce various approaches adopting several principles to control fluids on papers. Fluid manipulation technologies are classified into passive and active methods. While passive valves are structurally simple and easy to fabricate, they are difficult to control in terms of flow at a specific spatiotemporal condition. On the contrary, active valves are more complicated and mostly require external systems, but they provide much freedom of fluid manipulation and programmable operation. Both technologies have been revolutionized in the way to compensate for their limitations, and their advances will lead to improved performance of μPADs, increasing the level of healthcare around the world. © 2020 by the authors.1

The development and optimisation of a novel microfluidic immunoassay platform for point of care diagnostics

Protein biomarkers are important diagnostic tools for detection of non-communicable diseases, such as cancer and cardiovascular conditions. In order to be used as diagnostic tools they need to be detected at very low concentrations in biological samples (e.g. whole blood, serum or urine). This has been currently performed in central laboratories using expensive, bulky equipment and time consuming assays. [Continues.

The application of biomedical engineering techniques to the diagnosis and management of tropical diseases: A review

This paper reviews a number of biomedical engineering approaches to help aid in the detection and treatment of tropical diseases such as dengue, malaria, cholera, schistosomiasis, lymphatic filariasis, ebola, leprosy, leishmaniasis, and American trypanosomiasis (Chagas). Many different forms of non-invasive approaches such as ultrasound, echocardiography and electrocardiography, bioelectrical impedance, optical detection, simplified and rapid serological tests such as lab-on-chip and micro-/nano-fluidic platforms and medical support systems such as artificial intelligence clinical support systems are discussed. The paper also reviewed the novel clinical diagnosis and management systems using artificial intelligence and bioelectrical impedance techniques for dengue clinical applications