3D Printed Interdigitated Electrodes for Cardiac Biomarker Detection.

The identification of biomarkers has significant benefits for early disease diagnosis and treatment. Hence, there is an increasing demand for low-cost, disposable point-of-care diagnostic devices for rapid and specific biomarker detection, with good sensitivity and range. Interdigitated electrodes (IDEs) are among the most widely used transducers, especially in chemical and biological sensors, because of their high sensitivity, low cost, and straightforward manufacturing procedure. In this work, a simple 3D printed IDE structure has been developed for cardiac troponin I detection to indicate the risk of acute myocardial infarction (AMI). IDEs have been fabricated using 3D printing technique and the electrically conductive composite polylactic acid (PLA) filament being utilized for the fabrication of electrodes. The demonstrated cardiac troponin I sensor has a calculated quantification limit and detection limit of 0.233 ng ml-1 and 76.97 pg ml-1, respectively which are clinically significant ranges for AMI identification. Electrochemical analytical techniques, such as electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), were carried out for the detection of analyte concentration. Furthermore, using this fabrication methodology IDEs can be fabricated for under US$ 0.4 which can be utilized to detect several other biomarkers.

Benchmarking Power Generation From Multiple Wastewater Electrolytes in Microbial Fuel Cells With 3D Printed Disk-Electrodes.

Microbial Fuel Cells (MFCs) have recently gained attention, as they are inexpensive, green in nature, and sustainable. As per the report, by Allied Market Research the global market size of MFCs will increase from $ 264.8 million in 2021 to $ 452.2 million in 2030, growing at a CAGR of 4.5%. The present work is a comparative study of various types of electrolytes that can be used in MFCs. The working electrodes were printed using conducting graphene-based Polylactic Acid (PLA) filaments with the help of a 3D printer under the principle of the fused deposition method. Simulated electrolytes and natural environmental microbial electrolytes were used here. Also, electrolytes of pure E. coli culture were studied. Lake water reported the highest power density of 8.259 mW/cm2 while Stale E. Coli reported the lowest around 0.184 mW/cm2. The study comprehensively lists potential wastewaters that can fuel the MFCs. With the pioneering of various comparative studies of electrolytes, one can insight into the recruitment of electrolytes with high-performance benchmarks for miniaturized energy storage and other microelectronics applications.

Electrochemical Synthesis of Molecularly Imprinted Polymers for L-Tyrosine Detection.

L-Tyrosine (L-Tyr), a critical amino acid whose aberrant levels impact melanin and dopamine levels in human body while also increasing insulin resistance thereby increasing the risk of type 2 diabetes. The objective of this study was to detect the amount of L-Tyr in human fluids by tailored electrochemical synthesis of well adhered, homogenous and thin molecularly imprinted polymers (MIPs) by the electro-polymerization of pyrrole on glassy carbon electrode modified functionalized multi-walled carbon nanotubes. The key benefits of this procedure over previous imprinting techniques were the elimination of expensive materials like Au and tedious multi-step synthesis, for L-Tyr detection using a handheld potentiostat. The developed particles were characterized using Fourier Transform Infrared Spectroscopy, Scanning Electron Microscope, Chronoamperometry, and Cyclic Voltammetry. With strong reproducibility and stability, this optimized approach provides a rapid and effective method of preparing and sensing MIPs for the target analyte with a broad linear range of [Formula: see text] to [Formula: see text]. The Limit of Detection and Limit of Quantification were [Formula: see text] and [Formula: see text], respectively. The engineered sensor was validated for quantifying the concentrations of L-Tyr in human blood and serum samples, yielding satisfactory recovery and can be expanded in future to detect analytes simultaneous.

Electromicrofluidic Device for Interference-Free Rapid Antibiotic Susceptibility Testing of Escherichia coli from Real Samples.

Antimicrobial resistance (AMR) is a global health threat, progressively emerging as a significant public health issue. Therefore, an antibiotic susceptibility study is a powerful method for combating antimicrobial resistance. Antibiotic susceptibility study collectively helps in evaluating both genotypic and phenotypic resistance. However, current traditional antibiotic susceptibility study methods are time-consuming, laborious, and expensive. Hence, there is a pressing need to develop simple, rapid, miniature, and affordable devices to prevent antimicrobial resistance. Herein, a miniaturized, user-friendly device for the electrochemical antibiotic susceptibility study of Escherichia coli (E. coli) has been developed. In contrast to the traditional methods, the designed device has the rapid sensing ability to screen different antibiotics simultaneously, reducing the overall time of diagnosis. Screen-printed electrodes with integrated miniaturized reservoirs with a thermostat were developed. The designed device proffers simultaneous incubator-free culturing and detects antibiotic susceptibility within 6 h, seven times faster than the conventional method. Four antibiotics, namely amoxicillin-clavulanic acid, ciprofloxacin, ofloxacin, and cefpodoxime, were tested against E. coli. Tap water and synthetic urine samples were also tested for antibiotic susceptibility. The results show that the device could be used for antibiotic resistance susceptibility testing against E. coli with four antibiotics within six hours. The developed rapid, low-cost, user-friendly device will aid in antibiotic screening applications, enable the patient to receive the appropriate treatment, and help to lower the risk of anti-microbial resistance.

Effects of Plasma Treatment on the Surface and Photocatalytic Properties of Nanostructured SnO2-SiO2 Films.

In this work, we study the effects of treating nanostructured SnO2-SiO2 films derived by a sol-gel method with nitrogen and oxygen plasma. The structural and chemical properties of the films are closely investigated. To quantify surface site activity in the films following treatment, we employed a photocatalytic UV degradation test with brilliant green. Using X-ray photoelectron spectroscopy, it was found that treatment with oxygen plasma led to a high deviation in the stoichiometry of the SnO2 surface and even the appearance of a tin monoxide phase. These samples also exhibited a maximum photocatalytic activity. In contrast, treatment with nitrogen plasma did not lead to any noticeable changes in the material. However, increasing the power of the plasma source from 250 W to 500 W led to the appearance of an SnO fraction on the surface and a reduction in the photocatalytic activity. In general, all the types of plasma treatment tested led to amorphization in the SnO2-SiO2 samples.

A protocol to execute a lab-on-chip platform for simultaneous culture and electrochemical detection of bacteria.

Here, we present a protocol for a miniaturized microfluidic device that enables quantitative tracking of bacterial growth. We describe steps for fabricating a screen-printed electrode, a laser-induced graphene heater, and a microfluidic device with its integrations. We then detail the electrochemical detection of bacteria using a microfluidic fuel cell. The laser-induced graphene heater provides the temperature for the bacterial culture, and metabolic activity is recognized using a bacterial fuel cell. Please see Srikanth et al.1 for comprehensive information on the application and execution of this protocol.

Microfluidic Device Integrated With PDMS Microchannel and Unmodified ITO Glass Electrodes for Highly Sensitive, Specific, and Point-of-Care Detection of Copper and Mercury.

This work delves upon developing a two-layer plasma-bonded microfluidic device with a microchannel layer and electrodes for electroanalytical detection of heavy metal ions. The three-electrode system was realized on an ITO-glass slide by suitably etching the ITO layer with the help of CO2 laser. The microchannel layer was fabricated using a PDMS soft-lithography method wherein the mold created by maskless lithography. The optimized dimensions opted to develop a microfluidic device with length of 20 mm, width of 0.5 mm and gap of 1 mm. The device, with bare unmodified ITO electrodes, was tested to detect Cu and Hg by a portable potentiostat connected with a smartphone. The analytes were introduced in the microfluidic device with a peristaltic pump at an optimal flow rate of [Formula: see text]/min. The device exhibited sensitive electro-catalytic sensing of both the metals by achieving an oxidation peak at -0.4 V and 0.1 V for Cu and Hg respectively. Furthermore, square wave voltammetry (SWV) approach was used to analyze the scan rate effect and concentration effect. The device also used to simultaneously detect both the analytes. During simultaneous sensing of Hg and Cu, the linear range was observed between [Formula: see text] to [Formula: see text], the limit of detection (LOD) was found to be [Formula: see text] and [Formula: see text] for Cu and Hg respectively. Further, no interference with other co-existing metal ions was found manifesting the specificity of the device to Cu and Hg. Finally, the device was successfully tested with real samples like tap water, lake water, and serum with remarkable recovery percentages. Such portable devices pave way for detecting various heavy metal ions in a point-of-care environment. The developed device can also be used for detection of other heavy metals like cadmium, lead, zinc etc., by modifying the working electrode with the various nanocomposites.

Review and Perspective: Gas Separation and Discrimination Technologies for Current Gas Sensors in Environmental Applications.

Presently, numerous state-of-the-art approaches are being adapted for gas sensing and monitoring. These include hazardous gas leak detection as well as ambient air monitoring. Photoionization detectors, electrochemical sensors, and optical infrared sensors are a few of the commonly widely used technologies. Extensive reviews on the current state of gas sensors have been summarized. These sensors, which are either nonselective or semiselective, are affected by unwanted analytes. On the other hand, volatile organic compounds (VOCs) can be heavily mixed in many vapor intrusion situations. To determine the individual VOCs in a highly mixed gas sample using nonselective or semiselective gas sensors, gas separation and discrimination technologies are highly warranted. These technologies include gas permeable membranes, metal-organic frameworks, microfluidics and IR bandpass filters for different sensors, respectively. The majority of these gas separation and discrimination technologies are currently being developed and evaluated in laboratory-controlled environments and have not yet been extensively utilized in the field for vapor intrusion monitoring. These technologies show promise for continued development and application in the field for more complex gas mixtures. Hence, the present review focuses on the perspectives and a summary of the existing gas separation and discrimination technologies for the currently popular reported gas sensors in environmental applications.

Optimized porous carbon-fibre microelectrode for multiplexed, highly reproducible and repeatable detection of heavy metals in real water samples.

This work demonstrates the simultaneous identification of four hazardous heavy metals in water samples, namely copper, lead, cadmium, and mercury. A simple yet selective electrode with the simplest fabrication procedure was used. The modified porous carbon threads coated with gold nanoparticles (AuNPs) was employed as a working electrode. The surface chemistry and morphology of the AuNPs deposited porous carbon thread surface were examined. The electrocatalytic activity of the metals on the Au-modified thread surface was observed using the differential pulse voltammetry (DPV) technique. Furthermore, all four metal ions were detected simultaneously, and no interference was observed. Individual and simultaneous experiments to test the impact of concentration revealed that the limit of detection (LoD) was observed to be 1.126 µM, 1.419 µM, 0.966 µM, 0.736 µM for the Cd2+, Pb2+, Cu2+, and Hg2+ metal ions respectively in a linear concentration range of 10-110 µM of each. Subsequently, the study of pH, interference with coexisting metal ions, repeatability study, and stability analysis was also performed. A real sample analysis utilising three different lake water samples is also carried out to further understand the application of the proposed sensor. A good recovery rate is achieved, and the results are reported. This work paves way for the on-field applicability of the present heavy metal detection platform.

Portable Electrochemical Platform With Carbon Fibre Microelectrodes Integrated on an OHP Sheet for Snake Venom Analysis.

Snake bite is a serious medical emergency often leading to untimely fatalities. Serotherapy is the only treatment method adapted for this, whose efficacy depends on identification of the Snake species and venom type. As a specific antivenom has to be implicated for saving the victim, in most of the cases, such identification is challenging, thus, leading to mortality due to delay in treatment or side effects of injecting polymeric non-specific antivenom. Therefore, a point-of-care, venom specific detection device could be an impactful diagnostic tool. Herein, a prototype of miniaturized electrochemical sensing platform is presented for detection of Crotaline, venom from various common pit viper snakes. A three electrode based micro-platform with carbon fibre microelectrode, modified with mesoporous carbon, embedded and laminated in commercial OHP sheet, has been developed. The dimensions of the miniaturized platform was 25 mm ×35 mm, size of electrode was 0.5 mm ×25 mm with an electrochemical testing zone of diameter 10 mm, electrode spacing as 3 mm. The microscopic characterization revealed immobilization of porous carbon on fine fibrous structure. The device gave highly stable and sensitive electro-catalytic oxidation of Crotaline at E'= at 0.81 V, and provided a linear range of 50- [Formula: see text], limit of detection as [Formula: see text] and limit of quantification as [Formula: see text]. The device exhibited negligible interference from physiological blood serum biochemicals, high stability and reproducibility. Further, real blood serum samples, analysis via standard addition approach, was performed which showcased appreciable recovery values confirming the practical applicability of the device.

Modified Ultra Micro-Carbon Electrode for Efficient Ammonia Sensing for Water Quality Assessment.

Ammonia is one of the most prominent and hazardous water pollutants; hence its selective and sensitive detection in water is crucial for monitoring water quality and determining its usability. In the present work, a simple, cost-effective electrochemical sensor for the detection of ammonia is presented. Multi-walled carbon nanotubes modified ultra-micro-carbon thread electrode (UME/MWCNT) has been realized. The electro-catalytic activity of ammonia is studied by voltammetry and amperometry techniques and the results are presented. The microscopic characterization of UME/MWCNT for surface morphology analysis was also carried out. Further, the UME/MWCNT based electrochemical sensor was tested for its practical application by exploring various parameters like the effect of scan rate, pH and interference from co-existing bio-chemicals like nitrate, nitrite, phosphate, hydrazine, H2 [Formula: see text] uric acid, ascorbic acid and dopamine along with real sample analysis. The developed sensor can efficiently detect ammonia in a linear range of [Formula: see text] to 1 mM which is well within the permissible safe drinking water limit. The limit of detection (LoD) and limit of quantification (LoQ) obtained for the developed sensor were [Formula: see text] and [Formula: see text] respectively. The negligible interference, good reproducibility, and appreciable recovery values indicated the potential of the developed UME for real-time ammonia detection. As a flexible electrode, UME can be further modified and fabricated as a microfluidic or a miniaturized device for a portable electrochemical sensing platform in future.

Three Different Rapidly Prototyped Polymeric Substrates With Interdigitated Electrodes for Escherichia coli Sensing: A Comparative Study.

This work delves upon the development of different types of miniaturized and 3D printed devices having interdigitated electrodes (IDEs) for the detection of Escherichia coli (E. coli) bacteria. The IDEs were fabricated using different approaches including laser-induced graphene (LIG) on polyamide, direct laser writing on glass, and polymeric 3D printing technique, and their suitability for bacteria detection has been compared. The electrochemical impedance spectroscopy (EIS) technique was employed to detect the E. coli bacteria in the prepared miniaturized devices, and the sensory response was compared. EIS was performed in the frequency range between 1 Hz to 1 MHz to record the bacterial growth and activities as a function of change in electrical impedance, and detection performance of the different miniaturized devices with IDEs were compared. It was observed that the LIG-based IDE sensor provided better sensitivity compared to that of the other two approaches. The obtained results indicate that the magnitude of impedance changes by around 2.5 [Formula: see text] per doubling of E.coli cells. With fast and flexible fabrication process capabilities, such microdevices may be used as suitable IDE sensors for microscale pathogenic detection for biomedical and clinical analysis.

Microfluidic electrochemical device for real-time culturing and interference-free detection of Escherichia coli.

Bacterial contamination and infection is a major health concern today leading to the significance of its detection. Being lab-based bacterial culturing processes, the present approaches are time consuming and require trained skillset. An economical, and miniaturized lab-on-chip device, capable of simultaneous detection of bacterial growth, could be a benchmarking tool for monitoring the bacterial contamination. Herein, the microfluidic-based electrochemical device for a fast, susceptible, detection of Escherichia coli was developed. The device could aid incubator free bacteria culturing in the ambient atmosphere and simultaneously monitor and detect the growth electrochemically. A three-electrode system, integrated with a reservoir and a portable thermostat temperature controller was fabricated and assembled. To achieve this, three-electrodes were embedded on the microfluidic device by screen-printing carbon paste, and the working electrode was enhanced by graphitized mesoporous carbon. Cyclic voltammetry response was noted as the function of concentration and growth of Escherichia Coli in the reservoir. The device gave a linear bacterial concentration range of 0.336 × 1012 to 40 × 1012 CFU mL-1, detection limit of 0.35 CFU mL-1 and the quantification limit of 1.05 CFU mL-1 which was less than the maximum allowable limit. The developed platform was further used to detect and continuously monitor the bacterial growth in the real sample (mango juice) for a period of 36 h. Finally, the interference from other common bacteria on the electrode selectivity was also investigated. Such approach in being further modified for specific sensing of bacteria in patients suffering from different diseases such as corneal ulcers, Diarrhea, tuberculosis, leprosy, and syphilis.

Disposable Miniaturized Electrochemical Sensing Platform With Laser-Induced Reduced Graphene Oxide Electrodes for Multiplexed Biochemical Analysis.

Metabolic biomarkers, such as Dopamine (DA), Uric acid (UA), and Ascorbic acid (AA), have significant roles in determining the physiological functioning of the human body. These are often analyzed through clinical lab-based procedures which are bulky and require skilled technicians. In view of this, the design, development, and fabrication of a portable, cost-effective, user-friendly, and disposable device for electro-analytical detection, leading to point-of-care (POC) detection of these metabolic biomarkers is a pressing need. This work reports a laser-induced reduced graphene oxide (LIrGO) based miniaturized paper device fabricated by laser ablation of a lab-grade paper using a blue diode laser (450 nm). A three-electrode electrochemical platform was designed with the LIrGO electrodes, whereby bare rGO electrodes were employed as working and counter electrodes, and Ag/AgCl ink-coated rGO was used as the reference electrode. The device was characterized morphologically by Scanning Electron Microscopy (SEM) and electrochemically by a potentiostat. The prepared device was subjected to electrochemical sensing of Dopamine (DA), Uric Acid (UA), and Ascorbic Acid (AA). Furthermore, the effects of several sensory parameters, such as concentration, pH, and interference, were analyzed. A linear range of 10- [Formula: see text] was obtained for all three analytes with the limit of detection (LoD) being [Formula: see text], [Formula: see text], [Formula: see text], and the limit of quantification (LoQ) being [Formula: see text], [Formula: see text], [Formula: see text] for DA, UA and AA, respectively. Finally, the device was tested for non-interference with co-analytes and validated by testing a real sample of human blood serum. This work demonstrates a proof-of-principle of utilizing bare LIrGO for selective sensing which will open door to multiplexed and POC sensing.

Laser induced graphanized microfluidic devices.

With the advent of cyber-physical system-based automation and intelligence, the development of flexible and wearable devices has dramatically enhanced. Evidently, this has led to the thrust to realize standalone and sufficiently-self-powered miniaturized devices for a variety of sensing and monitoring applications. To this end, a range of aspects needs to be carefully and synergistically optimized. These include the choice of material, micro-reservoir to suitably place the analytes, integrable electrodes, detection mechanism, microprocessor/microcontroller architecture, signal-processing, software, etc. In this context, several researchers are working toward developing novel flexible devices having a micro-reservoir, both in flow-through and stationary phases, integrated with graphanized zones created by simple benchtop lasers. Various substrates, like different kinds of cloths, papers, and polymers, have been harnessed to develop laser-ablated graphene regions along with a micro-reservoir to aptly place various analytes to be sensed/monitored. Likewise, similar substrates have been utilized for energy harvesting by fuel cell or solar routes and supercapacitor-based energy storage. Overall, realization of a prototype is envisioned by integrating various sub-systems, including sensory, energy harvesting, energy storage, and IoT sub-systems, on a single mini-platform. In this work, the diversified work toward developing such prototypes will be showcased and current and future commercialization potential will be projected.

Miniaturized 3D printed electrochemical platform with optimized Fibrous carbon electrode for non-interfering hypochlorite sensing.

3D printing technology based electrochemical device can provide ease of fabrication, cost effectiveness, rapid detection and lower limit of detection. Herein, a novel, customized, portable and inexpensive 3D printed electrochemical device, has been presented. Fibrous carbon Toray paper, deposited with gold nanoparticles through electrodeposition, used as a working electrode which Further device was tested with 1 mM sodium hypochlorite using cyclic voltammetry (CV) and square wave voltammetry (SWV) in 0.1 M PBS. Hypochlorite has a pivotal role in supporting the growing chemical and paper industries and finds diverse uses in several clinical applications. It is primarily used for disinfecting food, water and surfaces. The scan rate study was carried out from 20 mVs-1 to 250 mVs-1 using cyclic voltammetry technique. The diffusion coefficient obtained from scan rate effect was 1.39 × 10-6 cm2s-1. The concentration range was evaluated with SWV technique, in a linear range of 0.6 µM-40 µM, with a detection limit of 0.7 µM. The device was further analyzed to ensure non-interference from co-existing chemicals like sodium chloride, potassium nitrate, sodium carbonate, sodium nitrite. Real sample analysis was done with sea, artificial sea and tap water with impressive recovery values. In summary, the developed working electrode can be customized and modified based on testing analyte; thus, the proposed device can be used for various other biochemical analytes.

Integrated Microfluidic Device With Carbon-Thread Microelectrodes for Electrochemical DNA Elemental Analysis.

Evidently, any alternation in the concentration of the essential DNA elements, adenine (A), guanine (G), cytosine (C), and thymine (T), leads to several deformities in the physiological process causing various disorders. So, to realize a simple and precise technique for simultaneous determination of the DNA elements continue to remain a challenge. Microfluidic devices offer numerous advantage, such as low volume consumption, rapid response, highly sensitive and accurate real time analysis, for point of care testing (POCT). Herein, a microfluidic electrochemical device has been developed with three electrodes fabricated using a carbon-thread microelectrode (CTME) for DNA elemental detection. CTME, functionalized with graphitize mesoporous carbon (GMC), worked as a working electrode, bare CTME functioned as an auxiliary electrode while CTME coated with Ag/AgCl ink performed as a reference electrode. The developed device was used for evaluating individual DNA elemental base pairs simultaneously using various electrochemical techniques. The anodic peak current obtained for the DNA bases were 0.56 ± 0.04 V (G), 0.92 ± 0.02 V (A), 1.09 ± 0.05 V (T) and 1.24 ± 0.04 V (C) in a potential window of 0.2 V to 1.5 V. The device was corroborated for simultaneous sensing, and detection limits were found to be [Formula: see text] (G), [Formula: see text] (A), [Formula: see text] (T) and [Formula: see text] (C) in the linear range of [Formula: see text] - [Formula: see text]. Finally, the device was successfully used for instantaneous determination of DNA bases in the human blood serum sample. Overall, this work demonstrates the use of a simple microfluidic device with CTMEs for electrochemical determination of DNA bases amenable for POCT.

Electrochemical Mini-Platform With Thread- Based Electrodes for Interference Free Arsenic Detection.

Herein, a fully integrated thread/textile-based electrochemical sensing device has been demonstrated. A hydrophilic conductive carbon thread, chemically modified with gold nanoparticles through an electrodeposition process, was used as a working electrode (WE). The hydrophilic thread coated with Ag/AgCl and an unmodified bare hydrophilic thread were used as reference electrode (RE) and counter electrode (CE) respectively. The device was fabricated with hydrophilic conductive carbon threads supported by capillary tubes and these integrated electrodes were placed in a 2 mL glass vial. The physico-chemical characterization of the working electrode was carried out using SEM (scanning electron microscopy) and X-ray photoelectron spectroscopy (XPS). Furthermore, the fabricated sensing platform, was tested for electrochemical sensing of arsenic. The electrocatalytic oxidation activity of arsenic in the designed platform was investigated via cyclic voltammetry (CV) and square wave Voltammetry (SWV). An oxidation peak at -0.4 V corresponding to the oxidation of arsenic was obtained. Scan rate effect was performed using CV analysis and the diffusion coefficient was found to be 2.478×10-10 with a regression coefficient of R2 = 0.9647. Further, concentration effect was accomplished in the linear range 0.4 µ M to 60 µ M. The limit of detection was obtained as 0.416 µ M. For the practical application, effect of interference from other chemicals and real sample analysis from the tap water and blood serum sample was carried out which gave remarkable recovery values.

Optimized ink jetted paper device for electroanalytical detection of picric acid.

Picric acid (PA) is one of the essential components utilized in manufacturing of explosives. Therefore, the detection of trace amount of PA is critical in forensic science, criminal investigation, military security and environmental safety. Owing to these attributes, development of a simple, rapid and point-of-care (POC) analytical method for PA detection and quantification is crucial. Herein, a low-cost, POC, ink jetted paper device has been developed for electroanalytical detection of PA. Inkjet printing is an economic fabrication process used for extruding several nanomaterials with diversified applications. By improving the ink viscosity, inkjet printers can simplify the fabrication of paper-based electrochemical sensor, and provide easy, fast, environmental friendly and viable for large scale production sensors, thereby adding its commercialization potential. In this work, a commercially available circuit board printer and an inexpensive high viscosity carbon conductive ink were used to print an electrochemical paper device. The fabricated device was used for electrochemical detection of PA using cyclic voltammetry (CV) and wave voltammetry (SWV). Various parameters like effect of potential scan rate from 10 mVs-1 to 300 mVs-1, effect of variable PA concentration effect was studied. A linear concentration range of 4 µM to 60 µM was obtained. For a working electrode of 7 mm2 surface area, the limit of detection (LOD) was 4.04 µM (922.56 ppb) which was less than the prescribed safe limit of 8 µM. Effect of interference with other chemicals was examined using SWV with the co-existing metals like zinc, lead, copper and mercury. Finally, real sample analysis for tap and lake water was successfully performed with the device. The developed cost-effective paper-based ink-jetted platform, with further fine-tuning and surface modifications, can be used for sensing various analytes as a point-of-care device.

Smartphone enabled miniaturized temperature controller platform to synthesize nio/cuo nanoparticles for electrochemical sensing and nanomicelles for ocular drug delivery applications.

Undoubtedly, various kinds of nanomaterials are of great significance due to their enormous applications in diverse areas. The structure and productivity of nanomaterials are heavily dependent on the process used for their synthesis. The synthesizing process plays a vital role in shaping nanomaterials effectively for better productivity. The conventional method requires expensive and massive thermal instruments, a huge volume of reagents. This paper aims to develop an Automatic Miniaturized Temperature Controller (AMTC) device for the synthesis of nickel oxide (NiO), copper oxide (CuO) nanoparticles, and nanomicelles. The device features a low-cost, miniaturized, easy-to-operate with plug-and-play power source, precise temperature control, and geotagged real-time data logging facility for the producing nanoparticles. With a temperature accuracy of ± 2 °C, NiO and CuO nanoparticles, and nanomicelles are synthesized on AMTC device, and are subjected to different characterizations to analyze their morphological structure. The obtained mean size of NiO and CuO is 27.14 nm and 85.13 nm respectively. As a proof-of-principle, the synthesized NiO and CuO nanomaterials are validated for electrochemical sensing of dopamine, hydrazine, and uric acid. Furthermore, the study is conducted, wherein, Dexamethasone (Dex) loaded nanomicelles are developed using AMTC device and compared to the conventional thin-film hydration method. Subsequently, as a proof-of-application, the developed nanomicelles are evaluated for transcorneal penetration using exvivo goat cornea model. Ultimately, the proposed device can be utilized for performing a variety of controlled thermal reactions on a minuscule platform with an integrated and miniaturized approach for various applications.