Technology Overview

The developed technology comprises two photoactive plant-derived materials for effective control of mosquito vector and microbial infection respectively.

A novel sunlight-activated larvicide has been developed from a plant source that are lethal and effective against Aedes mosquito larvae while remaining non-toxic to other non-translucent aquatic organisms and environment. This larvicide could be a new eco-friendly tool in the fight against mosquito-borne diseases like dengue and zika. It provides a new avenue for the control of the mosquito vector population by targeting the mosquito larvae before they become adult mosquitoes.

The stabilised form of a photoactive plant-based antimicrobial agent has been developed to protect it from environmental degradation. The enhanced environmental stability of this natural compound has made it suitable to be incorporated as additive in various materials for the self-disinfecting product applications and may provide a “greener solution” to limit the spread of pathogens and transmission of infections by indirect contact.

These photoactive plant-based materials are effective alternatives of conventional insecticides or antimicrobial agents as they produce highly reactive oxygen species (ROS) when activated by visible light. These reactive oxygen species display multi-targeted killing mechanism on translucent organisms such as mosquito larvae and microbes, which may limit the development of resistance in these species and provide an effective and sustainable solution to these public health challenges.

Technology Features, Specifications and Advantages

The photoactive agents are derived from plant sources that are cost-effective and easily available. They are environmentally friendly and effective. The final products were obtained by single-step chemical synthesis method which is easily scalable.

The sunlight activated larvicide may solve the problem of mosquitoes breeding as it targets mosquito larvae instead of adult mosquitoes. It can be applied in low concentrations to effectively kill the mosquito larvae. It is also harmless to other aquatic animals as sunlight can only penetrate through the translucent organism like mosquito larvae to activate the larvicide. It may also reduce the use of pesticides and frequency of fogging.

The stabilisation of the plant-based antimicrobial agent is achieved by a single-step chemical reaction. Elemental and spectroscopic analyses of the stabilised product have shown that it is more stable in the environment than in its natural precursor form. The photosensitisation and antimicrobial properties of the natural compound are retained after the stabilisation treatment. Furthermore, it displays dual antimicrobial function in dark and light environment, while the antimicrobial activity is enhanced in the presence of visible light.

Potential Applications

The larvicide can be included in mosquito vector control programme to address the challenge of increasing mosquito population in Singapore and other tropical countries. It is capable of reducing the number of Aedes mosquito, before they reach adult stage thus preventing the spread of diseases like malaria, dengue and zika; the diseases that infect nearly 700 million people each year resulting in greater than one million deaths globally. The annual economic cost of dengue illness in Asia is estimated at US$2 billion, excluding the costs of preventive and vector control efforts. The larvicide can be applied directly to mosquito breeding sites. This will reduce the frequency of fogging to terminate adult mosquitoes. The pesticides used in the fogging kill mosquito predators along with mosquitoes and cause adverse side effects on human.

In the current Covid-19 situation, consumers all over the world are becoming more interested in self-disinfecting products to have a sense of reassurance of hygiene and safety. Self-disinfection can be achieved by incorporation of antimicrobial materials in coatings. However, the overuse of common antimicrobial agents may have adverse human health impacts related to antimicrobial resistance. The natural photoactive antimicrobial agent is an effective alternative which can be incorporated into coating formulations to develop antimicrobial coatings for diverse surfaces including plastics, leather, wood, concrete and metal. In addition, this agent may have potential applications in fabric dye, personal care products and packaging materials.

Customer Benefits

Sunlight-activated Larvicide:

• Green and environmentally friendly solutions
• The larvicide killed almost 100% of Aedes larvae
• It is lethal to mosquito larvae at a very low concentrations thus require very small dosages to be effective
• It is projected to reduce 50% in man hours spent on mosquito fogging
• It is harmless to non-translucent organisms, and thus safe for other aquatic animals to ingest

Photo-active Antimicrobial Agent

• Sustainable and more environmentally friendly than conventional antimicrobials
• Easy to manufacture through a single-step chemical reaction
• Can be used as a form of infection control measure to create self-sterilising contact surfaces
• Limits the spread of pathogens by indirect contact