Browsing by Author "Lal K"

Now showing 1 - 5 of 5
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    Electrochemical and Optical Sensors for Real-Time Detection of Nitrate in Water
    (MDPI, 2023-08-11) Lal K; Jaywant S; Arif K
    The health and integrity of our water sources are vital for the existence of all forms of life. However, with the growth in population and anthropogenic activities, the quality of water is being impacted globally, particularly due to a widespread problem of nitrate contamination that poses numerous health risks. To address this issue, investigations into various detection methods for the development of in situ real-time monitoring devices have attracted the attention of many researchers. Among the most prominent detection methods are chromatography, colorimetry, electrochemistry, and spectroscopy. While all these methods have their pros and cons, electrochemical and optical methods have emerged as robust and efficient techniques that offer cost-effective, accurate, sensitive, and reliable measurements. This review provides an overview of techniques that are ideal for field-deployable nitrate sensing applications, with an emphasis on electrochemical and optical detection methods. It discusses the underlying principles, recent advances, and various measurement techniques. Additionally, the review explores the current developments in real-time nitrate sensors and discusses the challenges of real-time implementation.
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    Laser ablation assisted micropattern screen printed transduction electrodes for sensing applications
    (Nature Publishing Group, 28/04/2022) Rehmani MAA; Lal K; Shaukat A; Arif K
    In this work we present a facile method for the fabrication of several capacitive transduction electrodes for sensing applications. To prepare the electrodes, line widths up to 300 μm were produced on polymethyl methacrylate (PMMA) substrate using a common workshop laser engraving machine. The geometries prepared with the laser ablation process were characterised by optical microscopy for consistency and accuracy. Later, the geometries were coated with functional polymer porous cellulose decorated sensing layer for humidity sensing. The resulting sensors were tested at various relative humidity (RH) levels. In general, good sensing response was produced by the sensors with sensitivities ranging from 0.13 to 2.37 pF/%RH. In ambient conditions the response time of 10 s was noticed for all the fabricated sensors. Moreover, experimental results show that the sensitivity of the fabricated sensors depends highly on the geometry and by changing the electrode geometry sensitivity increases up to 5 times can be achieved with the same sensing layer. The simplicity of the fabrication process and higher sensitivity resulting from the electrode designs is expected to enable the application of the proposed electrodes not only in air quality sensors but also in many other areas such as touch or tactile sensors.
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    Low-cost IoT based system for lake water quality monitoring
    (Public Library of Science (PLoS), 2024-03-28) Lal K; Menon S; Noble F; Arif K
    Water quality monitoring is a critical process in maintaining the well-being of aquatic ecosystems and ensuring growth of the surrounding environment. Clean water supports and maintains the health, livelihoods, and ecological balance of the ecosystem as a whole. Regular assessment of water quality is essential to ensure clean and reliable water is available to everyone. This requires regular measurement of pollutants or contaminants in water that can be monitored in real-time. Hence, this research showcases a system that consists of low-cost sensors used to measure five basic parameters of water quality that are: turbidity, total dissolved solids, temperature, pH, and dissolved oxygen. The system incorporates electronics and IoT technology that are powered by a solar charged lead acid battery. The data gathered from the sensors was stored locally on a micro-SD card with live updates that could be viewed on a mobile device when in proximity to the system. Data was gathered from three different bodies of water over a span of three weeks, precisely during the seasonal transition from autumn to winter. We adopted a water sampling technique since our low-cost sensors were not designed for continuous submersion. The results show that the temperature drops gradually during this period and an inversely proportional relationship between pH and temperature could be observed. The concentration of total dissolved solids decreased during rainy periods with a variation in turbidity. The deployed system was robust and autonomous that effectively monitored the quality of water in real-time with scope of adding more sensors and employing Industry 4.0 paradigm to predict variations in water quality.
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    Methamphetamine detection using nanoparticle-based biosensors: A comprehensive review
    (Elsevier BV, 2022-12) Lal K; Noble F; Arif K
    Drug abuse is a global issue, requiring diverse techniques for recognition of drug of interest. One such illicit drug that is abused worldwide is Methamphetamine (METH). It is an addictive and illicit substance that severely affects the central nervous system. Similar to many other illicit substances, recognition of METH in biological fluids and in more diverse matrices such as wastewater, is a topic of great interest to the government and law enforcement agencies. With the rise of nanotechnology that relies on exploiting the properties of certain materials at a scale down to their nanometer range in conjunction with aptamers, molecularly imprinted polymers as well as antibodies have gained much attention over the last decade. The scope and appositeness of nanomaterials have significant characteristics that are highly suitable for recognition of illicit chemical compounds such as METH. This comprehensive review focuses on the detection of METH using nanoparticles in real world samples such as biological fluids and wastewater, while discussing varieties of materials used as nanoparticles and that aid in its recognition. It also offers insights into future opportunities and challenges that come with the use of nanotechnology in sensing applications.
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    The Role of Science, Technology, and Innovation for Transforming Food Systems in Asia
    (Springer Nature Switzerland AG, 2023-01-02) Moughan PJ; Chamovitz DA; Ayyappan S; Tanticharoen M; Lal K; Kim YH; von Braun J; Afsana K; Fresco LO; Hassan MHA
    This chapter focusses on the role of science, technology and innovation (STI) in transforming the food systems of Asia and the Pacific to achieve long-term environmentally sustainable food and nutritional security (FNS). A “whole of systems” approach is required to address the issues, and that work is urgently needed to define ‘healthy’ diets for different regions, societies and cultures. Emphasis should shift from the provision of calories to the supply of balanced patterns of all essential nutrients, and the ‘holistic’ properties of foods should be recognised. The chapter identifies countries and regions, within Asia, considered to be at particularly high risk for future food insecurity. Systems analysis should be applied across the agricultural and food sectors of these countries to identify the actual technical and other impediments to FNS. It is envisaged that the results from such an analysis would be used to formulate a ‘blueprint’ for agricultural and food STI in Asia. Overarching recommendations are the establishment of a trans-national funding mechanism for the entire region, focussing on targeted interdisciplinary STI, and the establishment of regional centres of excellence for research, education and extension, focussing on the identified key areas of opportunity. It was concluded that there is an urgent need for investment and action.