The two-dimensional layer of molybdenum disulfide (MoS₂) exhibits promising prospects in the applications of optoelectronics and valleytronics.

Colorimetric biosensors can be used to detect a particular analyte through color changes easily by naked eyes or simple portable optical detectors for quantitative measurement. Thus, it is highly attractive for point-of-care detections of harmful viruses to prevent potential pandemic outbreak, as antiviral medication must be administered in a timely fashion. This review paper summaries existing and emerging techniques that can be employed to detect viruses through colorimetric assay design with detailed discussion of their sensing principles, performances as well as pros and cons, with an aim to provide guideline on the selection of suitable colorimetric biosensors for detecting different species of viruses. Among the colorimetric methods for virus detections, loop-mediated isothermal amplification (LAMP) method is more favourable for its faster detection, high efficiency, cheaper cost, and more reliable with high reproducible assay results. Nanoparticle-based colorimetric biosensors, on the other hand, are most suitable to be fabricated into lateral flow or lab-on-a-chip devices, and can be coupled with LAMP or portable PCR systems for highly sensitive on-site detection of viruses, which is very critical for early diagnosis of virus infections and to prevent outbreak in a swift and controlled manner.

We designed a stable and efficient CuO based photocathode by tuning the crystallinity and surface morphology of films by rapid thermal treatment. The role of the annealing temperature on film crystallinity, optical absorption and grain size is studied. The impact of these parameters upon the photocatalytic water splitting performance of CuO films is investigated. We observed that a higher annealing temperature improves the film crystallinity and increases the grain size of CuO film, which significantly enhance the photocurrent generation capability. Rapid thermal annealing at 550 °C is found the best temperature to achieve the highest PEC performance. The thickness of the CuO photocathodes is also optimized and we observed that 550 nm thick films results in the highest photocurrent of 1.68 mA cm⁻². Our optimized CuO photocathode has shown better stability against photo-corrosion and a 30% decrease in the initial value of photocurrent is measured after 15 min, while a 60% decrease in the photocurrent is noticed in case of the as-deposited film.

Multilayer coating structure comprising a copper (Cu) layer sandwiched between titanium dioxide (TiO₂) were demonstrated as a transparent heat reflecting (THR) coating on glass for energy-saving window application. The main highlight is the utilization of Cu, a low-cost material, in-lieu of silver which is widely used in current commercial heat reflecting coating on glass. Color tunable transparent heat reflecting coating was realized through the design of multilayer structure and process optimization. The impact of thermal treatment on the overall performance of sputter deposited TiO₂/Cu/TiO₂ multilayer thin film on glass substrate is investigated in detail. Significant enhancement of transmittance in the visible range and reflectance in the infra-red (IR) region has been observed after thermal treatment of TiO₂/Cu/TiO₂ multilayer thin film at 500 °C due to the improvement of crystal quality of TiO₂. Highest visible transmittance of 90% and IR reflectance of 85% at a wavelength of 1200 nm are demonstrated for the TiO₂/Cu/TiO₂ multilayer thin film after annealing at 500 °C. Performance of TiO₂/Cu/TiO₂ heat reflector coating decreases after thermal treatment at 600 °C. The wear performance of the TiO₂/Cu/TiO₂ multilayer structure has been evaluated through scratch hardness test. The present work shows promising characteristics of Cu-based THR coating for energy-saving building industry.