Search

The rapid detection of biomolecules in a point of care (POC) setting is very important for diagnostic purposes. A platform which can provide this, whilst still being low cost and simple to use, is paper-based lateral flow immunoassays (LFIA). LFIA combine immunology and chromatography to detect a target by forming an immunocomplex with a label which traps them in a test zone. Qualitative analysis can be performed using the naked eye whilst quantitative analysis takes place by measuring the optical signal provided by the label at the test zone. There are numerous detection methods available; however, many suffer from low sensitivity and lack of multiplexing capabilities or are poor at providing POC quantitative analysis. An attractive method to overcome this is to use nanoparticles coated in Raman reporters as the labelled species and to analyse test zones using surface-enhanced Raman scattering (SERS). Due to the wide variety of metal nanoparticles, Raman reporter and laser excitations that are available, SERS-based LFIA have been adapted to identify and quantify multiple targets at once. Large Raman microscopes combined with long mapping times have limited the platform to the lab; however, by transferring the analysis to portable Raman instruments, rapid and quantitative measurements can be taken at the POC without any loss in sensitivity. Portable or handheld SERS-LFIA platforms can therefore be used anywhere, from modern clinics to remote and resource-poor settings. This review will present an overview of SERS-based LFIA platforms and the major recent advancements in multiplexing and portable and handheld detection with an outlook on the future of the platform. Graphical abstract

Background Australia has a high prevalence of regular use of methamphetamine. While half of people who use methamphetamine regularly are women, they make up only one third of people seeking treatment for methamphetamine use disorder. There is a lack of qualitative research into the facilitators and barriers to treatment for women who use methamphetamine regularly. The study seeks a better understanding of the experiences and treatment preferences of women who use methamphetamine, to inform person-centred changes in practice and policy that break down barriers to treatment. Methods We conducted semi-structured interviews with 11 women who frequently use methamphetamine (at least once a week), and who are not engaged in treatment. Women were recruited from health services surrounding a stimulant treatment centre at an inner-city hospital. Participants were asked about their methapmhetamine use and health service needs and preferences. Thematic analysis was completed using Nvivo® software. Results Three themes were developed from participants’ responses around experiences of regular methamphetamine use and treatment needs: 1. Resistance of stigmatised identity including dependence; 2. Interpersonal violence; 3. Institutionalised stigma. A fourth set of themes on service delivery preferences were also elicited, including continuity of care, integrated health care, and provision of non-judgmental services. Conclusion Gender-inclusive health care services for people who use methamphetamine should actively work to address stigma, support a relational approach to assessment and treatment, and seek to provide structurally competent health care that is trauma and violence informed, and integrated with other services. Findings may also have application for substance use disorders other than methamphetamine.

Minor structural changes in transition metal dichalcogenides can have dramatic effects on their electronic properties. This makes the quest for key parameters that enable a selective choice between the competing metallic and semiconducting phases in the 2D MoTe2 system compelling. Herein, we report the optimal conditions at which the choice of the initial seed layer dictates the type of crystal structure of atomically-thin MoTe2 films grown by chemical vapour deposition (CVD). When Mo metal is used as a seed layer, semiconducting 2H-MoTe2 is the only product. Conversely, MoO3 leads to the preferential growth of metallic 1T′-MoTe2. The control over phase growth allows for simultaneous deposition of both 2H-MoTe2 and 1T′-MoTe2 phases on a single substrate during one CVD reaction. Furthermore, Rhodamine 6G dye can be detected using few-layered 1T′-MoTe2 films down to 5 nM concentration, demonstrating surface enhanced Raman spectroscopy (SERS) with sensitivity several orders of magnitude higher than for bulk 1T′-MoTe2. The polymorphism of MoTe2 can be used to realize planar metallic/semiconducting homojunctions in 2D devices, greatly reducing the contact resistance. Here, the simultaneous growth of both phases is achieved on the same substrate by single-step chemical vapor deposition and seeding layer engineering.

Despite the clinical success of Androgen Receptor (AR)-targeted therapies, reactivation of AR signalling remains the main driver of castration-resistant prostate cancer (CRPC) progression. In this study, we perform a comprehensive unbiased characterisation of LNCaP cells chronically exposed to multiple AR inhibitors (ARI). Combined proteomics and metabolomics analyses implicate an acquired metabolic phenotype common in ARI-resistant cells and associated with perturbed glucose and lipid metabolism. To exploit this phenotype, we delineate a subset of proteins consistently associated with ARI resistance and highlight mitochondrial 2,4-dienoyl-CoA reductase (DECR1), an auxiliary enzyme of beta-oxidation, as a clinically relevant biomarker for CRPC. Mechanistically, DECR1 participates in redox homeostasis by controlling the balance between saturated and unsaturated phospholipids. DECR1 knockout induces ER stress and sensitises CRPC cells to ferroptosis. In vivo, DECR1 deletion impairs lipid metabolism and reduces CRPC tumour growth, emphasizing the importance of DECR1 in the development of treatment resistance., Androgen receptor (AR) signalling regulates cellular metabolism in prostate cancer. Here, the authors perform a proteomics and metabolomics characterisation of prostate cancer cells adapted to long-term resistance to AR inhibition and show rewiring of glucose and lipid metabolism, and further identify a signature associated with resistance to AR inhibition.

Surface-enhanced Raman scattering (SERS) is of interest for biomedical analysis and imaging because of its sensitivity, specificity and multiplexing capabilities. The successful application of SERS for in vivo biosensing requires probes to be biocompatible and procedures to be minimally invasive, challenges that have respectively been met by developing new nanoprobes and instrumentation. This Review presents recent developments in these areas, describing case studies in which sensors have been implemented, as well as outlining shortcomings that must be addressed before SERS sees clinical use. Surface-enhanced Raman scattering (SERS) is a physical phenomenon first discovered in 1974. SERS has since been exploited for bioanalysis because of its high sensitivity and multiplexing capabilities. This Review describes the progress made and problems faced with respect to using in vivo SERS in humans.

By using the fluorescent dye 6-propionyl-2-(N,N-dimethylamino) naphthalene (PRODAN) to monitor methanol generated during tetramethyl orthosilicate polymerization we have optimised the encapsulation of protein in silica sol-gel monoliths with respect to completion of hydrolysis and distillation in order to remove methanol such that protein can be added without denaturation. A minimum of 24 h at +4 °C was found to be required before hydrolysis is complete and 3-5 min of vacuum distillation at 50 °C and 300 mbar needed to remove methanol before the gel is formed. The biocompatibility of a tetramethyl orthosilicate sol-gel monolith was demonstrated by preserving the trimer protein allophycocyanin (APC) in its native form for up to 500 h. This obviates the previously essential requirement of covalently binding the trimer together in order to prevent dissociation into monomers and has enabled observation of native APC trimer in a sol-gel pore for the first time down to the single molecule level using combined fluorescence spectroscopy and confocal microscopy. The higher stability afforded by the protocol we describe could impact on the application of sol-gel materials to single-molecule studies of wider bearing such as protein folding and aggregation.

Following years of development, electronic paper is now entering ebooks, mobile phones and signs, and, as Duncan Graham-Rowe reports, is starting to gain the market acceptance that it has long strived for.

Holographic disk drives have long promised to eclipse even the latest high-density optical storage media. Now finally, as Duncan Graham-Rowe reports, the promising three-dimensional approach to storing information is about to make its debut.

With an ingredients list that includes rhino horn and tiger bone, traditional Asian medicine is on a collision course with wildlife preservation.

Modern living seems somehow to make our immune systems overly sensitive. Is cleanliness at fault — or something else?

The most controversial aspect of biofuels is the perceived competition for farmland. Will advances in biofuels and agriculture send this trade-off speeding towards the history books?

Strain gauges that change colour when stressed, bright backlight-free displays and highly sensitive biological sensors are all potential applications of tunable photonic crystal materials, reports Duncan Graham-Rowe.

Quantum dots — semiconductor nanocrystals that have custom designable optical properties — are opening up opportunities in the bio-imaging, display and lighting sectors, reports Duncan Graham-Rowe.

Photoacoustic imaging, using laser light to stimulate the emission of ultrasonic waves from tissue inside the human body, potentially offers a route to far deeper imaging than possible with conventional optical techniques, reports Duncan Graham-Rowe.

A visit to a dental clinic could cease to be a fearsome experience. Duncan Graham-Rowe finds out how lasers can help dentists to provide patients with more comfortable and convenient dental treatments.

The pollutant emissions and high-energy consumption of combustion engines using conventional spark plugs have long been serious environmental problems. Now, it has been demonstrated that lasers can provide a feasible green alternative. Duncan Graham-Rowe reports.

As the size of handheld gadgets decreases, their displays become harder to view. The solution could lie with integrated projectors that can project crisp, large images from mobile devices onto any chosen surface. Duncan Graham-Rowe reports.

Optical coherence tomography is rapidly becoming an important clinical tool, which provides high-resolution images that cannot be obtained by other means. Duncan Graham-Rowe spoke to a few of the companies developing the technology.

The idea of photovoltaic cells that can be printed onto thin, flexible plastic substrates are an enticing prospect for promoting solar energy generation. Duncan Graham-Rowe reports.

A growing number of enterprises around the world are now commercializing fibre Bragg grating sensors for sensing everything from temperature and pressure to vibration and strain. Duncan Graham-Rowe reports.

Imaging and spectroscopy equipment that exploits terahertz waves rather than visible or infrared light is now being developed by several firms around the world. Duncan Graham-Rowe spoke to a few of them to catch up with the latest developments.

Western conservation biologists working in Myanmar have been accused of colluding with a brutal military regime — charges they deny. Duncan Graham-Rowe reports from this pariah state. The military junta in Myanmar, formerly Burma, has been widely criticized for human rights abuses. But ecosystems there are under threat. Can conservationists from the West work there with a clear conscience?

Single-hulled ships are being rushed to the scrapyard in the wake of oil spills such as that of the Prestige. But will breaking them up cause environmental havoc too? Duncan Graham-Rowe finds out.

Several new drugs for treating chronic obstructive pulmonary disease are about to hit the market, with more in the pipeline.

Influenza mutates fast and spreads easily, earning a place among humanity's biggest killers.

New forms of advanced optical fibres featuring exotic glasses, carefully designed microstructures and cores that are either hollow, fluidic, semiconductor or piezoelectric are giving light guides a new lease of life, reports Duncan Graham-Rowe.

An array of polymer tips that can channel light to an underlying substrate can be used to generate intricate nanostructures with high throughput and over large areas.

Could lasers directly driven by sunlight help address the planet's energy generation problems? Japanese scientists are optimistic, reports Duncan Graham-Rowe.

Self-organizing liquid crystals could spawn a new breed of extremely useful and cheap tunable lasers. Such lasers may ultimately prove to be useful for creating flat-screen displays with better colours, enhanced sensors and compact medical instruments. Duncan Graham-Rowe takes a closer look.

With the world's love of cars showing little sign of abating, manufacturers are under increasing pressure to make vehicles less polluting and oil dependent. Duncan Graham-Rowe explores some of the technologies that could keep us on the road.

Shipping is one of the most fuel-efficient ways to move freight, but the industry still produces significant greenhouse-gas emissions, including more than a quarter of the world's nitrogen oxides emissions. And it also produces more sulphur dioxide emissions than all land transportation combined. In the latest of our Future Transport series, Duncan Graham-Rowe looks at the new wave in shipping.

Rail travel produces more than a third less emissions than road transport — even though trains carry 7% of traffic, they emit just 0.2% of the carbon monoxide, 2% of nitrogen oxides and 1% of the volatile organic compounds. Although electric passenger trains are relatively green, most of the world's trains are used for haulage and run on diesel. In the latest of our Future Transport series, Duncan Graham-Rowe sees trains switching to a greener track.