Themed collection Miniaturised Sensors & Diagnostics

Throughout the COVID-19 pandemic, we have witnessed the critical and expanding roles of testing.

Conventional gold electrode fabrication is too costly and laborious for implementation in low-resource settings (LRS). We review affordable, simple alternative fabrication methods, highlighting gold leaf electrodes, for LRS applications.

Single-use, disposable, point-of-care diagnostic devices carry great promise for global health, but present some challenges in terms of environmental sustainability. This perspective covers solutions to embed sustainability at the R&D and product development stages.

Review work on the challenges of paper-based NAATs covering sample-to-answer procedures along with the three main types of clinical samples as well as broader operational, scale up, and regulatory aspects of device development and implementation.

This review focuses on recent microfluidic technologies for label-free blood cell separation, detection and coupling with machine learning approaches.

The paper provides a comprehensive review on micro elastofluidic solutions for on-skin wearable devices.

We review recent advances in CRISPR-based nucleic acid detection using microfluidic devices and discuss the capabilities, limitations, and potential of this emerging technology.

This comprehensive review covers current methods used for biofilm detection in clinical and laboratory settings and noninvasive portable technologies for direct and indirect detection of biofilm growth and monitoring at the point of care.

This review critically analyzes the variety of methods to measure microfluidic flow rates as well as the development of metrological infrastructures for this purpose.

This review details how microfluidic technologies are disrupting the status quo, and facilitating the development of simple, affordable, and accessible integrated IVDs.

Microfluidic diagnostic (μDX) technologies miniaturize sensors and actuators to the length-scales that are relevant to biology: the micrometer scale to interact with cells and the nanometer scale to interrogate biology's molecular machinery.

Lateral flow assays (LFAs) have gained momentum for hormone biosensing, offering significant advantages over conventional techniques. This review demonstrates recent advances driving LFAs to the forefront of modern point-of-care hormone biosensing.

A review for quantum dots (QDs) as fluorescent nanoprobes for biosensing of biomolecules and cells based on microfluidic chips and for in vivo imaging of transplanted cells via an in vivo imaging system.

Diabetic retinopathy (DR) is the most common diabetic eye disease and the worldwide leading cause of vision loss in working-age adults.

This article reviews the rapid and unprecedented development, scaleup and deployment of POC devices in response to the COVID-19 pandemic and its implications for the future of diagnostics and digital health.

An integrated finger-actuated device utilising an acoustofluidic mixer, allows for the preparation of a filtered blood lysate from in under 3 minutes and without any pipetting.

A digitized microbubble detection mechanism delivered by a hybrid microfluidic/electronic system is devised for autonomous wearable high signal-to-noise ratio sweat rate monitoring.

Selection of bioreceptors is a resource- and time-consuming process that holds back the highly demanded implementation of rapid tests in emergency situations.

Two complementary low-cost methods of ITO electrode fabrication allowing small structures from 25 μm in width and removal of background ITO.

The graphical representation depicts a novel method of detecting the SARS-CoV-2 N gene without amplification using a label-free electrochemical DNA biosensor-based printed circuit board gold electrode (PCBGE).

The magnetically localized and wash-free fluorescence immunoassay (MLFIA) is a no-wash assay for directly measuring biomolecule (antigen and antibody) concentration, without mixing nor washing steps, from a body fluid (serum and plasma).

Integration of photonic sensors with tissue chips (TCs; also known as microphysiological systems or organ chips) enables real time monitoring of analytes produced by the TC or passed through a model tissue barrier.

A 3D-printed gradient generator for automated and expeditious on-chip antimicrobial susceptibility testing in a label-free manner is presented, paving the way towards clinical point-of-care applications.

A microfluidic platform for solid-state quantum sensing, enabling the measurement of various physical quantities for lab-on-a-chip applications.

A simple, portable, and low-cost microfluidic system-funnel adapted sensing tube (FAST) is developed as an integrated, power-free, and pipette-free biosensor for viral nucleic acids.

A microfluidic fully paper-based analytical device integrated with loop-mediated isothermal amplification (LAMP) and graphene oxide nanosensors was developed for the first time for rapid, low-cost, and quantitative detection of infectious diseases.

We demonstrated an instrument-free miniaturized adaptation of the laboratory gold standard methodology for direct estimation of plasma glucose from a drop of blood using a low-cost single-user-step paper-strip sensor interfaced with a smartphone.

The first synthesized cZIF-67@Cu-CAT nanoparticles were used as sensitive materials to prepare a dual response mode sensor.

With an advanced bioprinter, we print cancer cell spheroids directly into chip-based oxygen microsensors to determine single spheroid metabolism and drug responses.

This paper presents a novel pressure sensor to be used with microfluidic channels. The sensor is based on optical particle tracking, which turns a regular fluorescence microscope into a pressure measurement device.

This work reports rapid, label-free and specific detection of the HER2 antigen using a gallium nitride (GaN) high electron mobility transistor (HEMT).

The EDGE tensiometer allows access to nearly the full range of dynamic interfacial tension at relevant time scales for both droplet and bubble interfaces.

IoT-integrated multiplexed digital PCR system for detection of infectious diseases.

A microcantilever is fabricated by femtosecond laser direct writing for on-chip optofluidic sensing.

Miniaturized electrochemical and electrochemiluminescent biosensor using laser-induced graphene electrodes for highly sensitive and selective detection of C. parvum DNA.

This paper presents a new sample collection platform for a common bacterial infection, group A streptococcal (GAS) pharyngitis, also known as strep throat, caused by Streptococcus pyogenes.

The described microfluidic instrument performs real-time PCR (40 cycles) with comparable sensitivity to commercial instrumentation in under 10 minutes.

We develop a quantitative lateral flow assay (LFA) device that is able to measure the tear level of brain derived neurotrophic factor (BDNF). The device shows great potential to serve as an ideal platform for early detection of glaucoma.

This work demonstrated an on-chip virus analysis technology that can characterize multiple viruses in clinical samples with automated sample processing and detection.

BLENDER is a point-of-care device for rapid sample processing of large, robust tissue such as skin punch biopsies.

A rapid, fully automated, sensitive and specific SARS-CoV-2 detection method using RT-LAMP is performed on a centrifugal platform with active pneumatic pumping, a disposable, all-polymer-based microfluidic cartridge and lyophilized reagents.

The emerging single-molecule detection platform digital enzyme-linked immunosorbent assay (ELISA) can detect numerous proteins simultaneously at serum concentrations as low as picograms per milliliter.

An all-printed nanophotonic biochip is demonstrated for fast and easy-to-use quantitative detection of cardiac biomarkers. One drop of blood allows specific detection in 10 min. This is a potential platform for portable clinical diagnostics and home medical monitoring.

A parallel multistep digital analysis SlipChip for the parallel manipulation of a large number of droplets for digital biological analysis.

A microfluidic-based non-competitive fluorescence polarization immunoassay using a peptide as a tracer enables simple and rapid CD9 detection.

Proof of concept of the potential of an innovative double detection biochip based on GMR sensors as a diagnostic test.

Investigating fluid flow behavior during different acceleration and deceleration ramp rates for immunoassays.

The handheld, do-it-yourself ptychographic whole slide scanner for high-throughput digital pathology applications.

By using different customized microfluidic chips, a multifunctional rapid PCR platform allows fast screening of suspected cases within 15 min, followed by rapidly providing precise quantification of the SARS-CoV-2 virus.

A plantar pressure testing platform measured stress ranging from 35–47.5 kPa at each acupoint, determining the force at each point, and identifying abnormalities. It highlights the advantages of miniaturization, low cost and real-time detection.

A novel turbidity-sensor-integrated microfluidic device is developed to quickly measure the liquid–liquid phase separation boundaries.

Schematic of the microfluidic microwave detection of the SARS-CoV-2 virus. The detection relies on the frequency shift caused by the binding between the antibody coated on the microwave sensor and the SARS-CoV-2 antigen or virus.

We present a portable, highly integrated platform that employs isothermal recombinase polymerase amplification and giant magnetoresistive nanosensors to perform multiplex SNP genotyping at the point-of-care.

Passively pumped layer stack microfluidics allow for simple, inexpensive cyclic imaging with reduced reagent usage.

We present SPECTRA-tube (specimen transportation tube), a device that enables the dry stabilization and transportation of large volumes (>1 mL) of liquid specimens. We demonstrate its application in molecular and culture testing of tuberculosis.

A digital microfluidic system was developed for portable Zika virus diagnosis, featuring integrated, automated sample extraction and amplification.

A self-contained and integrated microfluidic nano-detection system was developed, demonstrating excellent performance for biosensing and analysis of molecular interactions.

Shear stresses generated by a silicon resonator embedded inside a microfluidic channel can rapidly and effectively lyse cells and homogenise whole blood. This significantly improves sensitivity of ATR-FTIR spectroscopy based diagnostic tests.

An epidermal, wearable bio-fluidic patch is demonstrated that facilitates simultaneous on-demand extraction, sampling, and storage of sweat and interstitial fluid (ISF) together with monitoring of their corresponding counterions.

High performance embedded electrochemical sensors fabricated with an inkjet printing system in a gut bilayer microfluidic chip monitored developmental and induced hypoxia.

A visual portable microfluidic experimental device (PMED) with multiple electric field regulation functions is designed to realize the integration and miniaturization of microfluidic systems.

A core–shell package design with auxetic metamaterial (AM) is proposed to configure the sensing performance of microfluidic strain sensor. By changing the structural design of AM, the sensor's directional sensitivity is effectively regulated.

Development of a novel fluid-handling assay with targeted sample delivery, independent redox preparation, and enhanced washing for fully automating single-step electrochemical immunosensing.

Wild-type SARS-CoV-2 or its D614G and N501Y mutations can be selectively amplified by tetra-primer ARMS-PCR and detected by two test lines on a single dual-color fluorescent test strip with a handheld wireless device.

Additively manufactured plastic cartridges and low-cost optical reader system to successfully detect the SARS-CoV-2 virus from saliva samples within 30 min.

An enhanced vertical flow assay that allows top readout has been developed and translated into a PoC application for detecting SARS-CoV-2 infection with saliva samples, providing a complementary antigen rapid test for COVID-19 surveillance.

We present an immunosensor based on a dual-gate oxide semiconductor thin-film transistor as a platform for detecting SARS-CoV-2.

Electrochemiluminescence was integrated onto a CMOS sensor with demonstration for detection of uric acid. The device has improved photon collection efficiency compared to a microscope-based system with the same field of view.

Herein, we describe the design of a portable device integrated with micromotors for real-time fluorescence sensing of (bio)markers.

By simply applying a sample, the traffic light type μPAD enables highly intuitive equipment-free naked-eye readout with no need for calibration, subjective interpretation or calculation.