Search results
1 – 10 of 225Adhithya Sreeram and Jayaraman Kathirvelan
Artificial fruit ripening is hazardous to mankind. In the recent past, artificial fruit ripening is increasing gradually due to its commercial benefits. To discriminate the type…
Abstract
Purpose
Artificial fruit ripening is hazardous to mankind. In the recent past, artificial fruit ripening is increasing gradually due to its commercial benefits. To discriminate the type of fruit ripening involved at the vendors’ side, there is a great demand for on-sight ethylene detection in a nondestructive manner. Therefore, this study aims to deal with a comparison of various laboratory and portable methods developed so far with high-performance metrics to identify the ethylene detection at fruit ripening site.
Design/methodology/approach
This paper focuses on various types of technologies proposed up to date in ethylene detection, fabrication methods and signal conditioning circuits for ethylene detection in parts per million and parts per billion levels. The authors have already developed an infrared (IR) sensor to detect ethylene and also developed a lab-based setup belonging to the electrochemical sensing methods to detect ethylene for the fruit ripening application.
Findings
The authors have developed an electrochemical sensor based on multi-walled carbon nanotubes whose performance is relatively higher than the sensors that were previously reported in terms of material, sensitivity and selectivity. For identifying the best sensing technology for optimization of ethylene detection for fruit ripening discrimination process, authors have developed an IR-based ethylene sensor and also semiconducting metal-oxide ethylene sensor which are all compared with literature-based comparable parameters. This review paper mainly focuses on the potential possibilities for developing portable ethylene sensing devices for investigation applications.
Originality/value
The authors have elaborately discussed the new chemical and physical methods of ethylene detection and quantification from their own developed methods and also the key findings of the methods proposed by fellow researchers working on this field. The authors would like to declare that the extensive analysis carried out in this technical survey could be used for developing a cost-effective and high-performance portable ethylene sensing device for fruit ripening and discrimination applications.
Details
Keywords
Jayaraman Kathirvelan and Rajagopalan Vijayaraghavan
This work encompasses the various laboratory-based and portable methods evolved in recent times for sensitive and selective detection of ethylene for fruit-ripening application…
Abstract
Purpose
This work encompasses the various laboratory-based and portable methods evolved in recent times for sensitive and selective detection of ethylene for fruit-ripening application. The role of ethylene in natural and artificial fruit ripening and the associated health hazards are well known. So there is a growing need for ethylene detection. This paper aims to highlight potential methods developed for ethylene detection by various researchers, including ours. Intense efforts by various researchers have been on since 2014 for societal benefits.
Design/methodology/approach
The paper focuses on types of sensors, fabrication methods and signal conditioning circuits for ethylene detection in ppm levels for various applications. The authors have already designed, developed a laboratory-based set-up belonging to the electrochemical and optical methods for detection of ethylene.
Findings
The authors have developed a carbon nanotube (CNT)-based chemical sensor whose performance is higher than the reported sensor in terms of material, sensitivity and response, the sensor element being multi-walled carbon nanotube (MWCNT) in comparison to single-walled carbon nanotube (SWCNT). Also the authors have developed infrared (IR)-based physical sensor for the first time based on the strong IR absorption of ethylene at 10.6 µm. These methods have been compared with literature based on comparable parameters. The review highlights the potential possibilities for development of portable device for field applications.
Originality/value
The authors have reported new chemical and physical sensors for ethylene detection and quantification. It is demonstrated that it could be used for fruit-ripening applications A comparison of reported methods and potential opportunities is discussed.
Details
Keywords
The purpose of this paper is to deal with an identification of a novel ink-jet printing sensor fabrication technology for fabricating flexible carbon heaters of macro and micro…
Abstract
Purpose
The purpose of this paper is to deal with an identification of a novel ink-jet printing sensor fabrication technology for fabricating flexible carbon heaters of macro and micro sizes, carbon interdigitated (IDT) electrodes and silver IDT electrodes. The technology involved in the proposed ink-jet printing method and materials used for the formulation of homemade nano-conductive inks (digital inks) are discussed in detail. The ink-jet printed flexible carbon heaters of different sizes (macro and micro) and carbon IDT electrodes and flexible silver IDT electrodes can be used as the flexible sensing layers in electrochemical gas sensors for sensitive and selective gas sensing applications. The characterization of ink-jet printed carbon heaters on Kapton substrate and its results are discussed. Similarly, the results of formulation of silver nano-conductive ink and printing of silver IDT electrodes on Kapton and its characterization are reported here for the first time.
Design/methodology/approach
Flexible carbon heaters of different sizes (macro and micro), carbon micro-IDT electrodes and silver IDT electrodes patterns were developed using AutoCAD 2D and printed on the Kapton (polyimide sheet) flexible substrate using the home-made nano-conductive inks with the help of EpsonT60 commercial piezo-head-based drop-on demand technology printer with standard printing options.
Findings
The proposed novel method is able to print heater patterns and IDT electrode patterns of approximately 12 µm and approximately 1 µm thickness, respectively, on flexible substrate using the home-made nano-conductive inks of carbon and silver by using a commercial low-cost printer. The home-made nano-conductive inks can be re-used for multiple prints up to six months shelf life. The resistance of the carbon heater was measured as 88 O under normal atmospheric condition. The novel flexible carbon heater was tested for its functionality and found to be satisfactory. The resistance of the silver IDT flexible electrodes was measured as 9.5 O which is better than the earlier works carried out in this paper.
Research limitations/implications
The main challenge is associated with cleaning of printing ink ejection system in the existing commercial printers. The customization of the existing printer in the near future can minimize the printing challenges.
Practical implications
The novel ink-jet printing technology proposed in this work is cost-effective, capable of achieving bulk production of flexible sensor elements, and consumes the least device fabrication time and high material yielding. The printing can be done with commercial piezo-head-based ink-jet printers with custom-prepared nano-conductive inks. There is a huge market potential for this paper.
Originality/value
Both the carbon heaters and silver IDT electrodes were printed on Kapton flexible substrate by using the commercial printer for the first time. The paper is promising the revolution in flexible low-cost sensor fabrication for mass production, and it is an alternate for thin film and thick sensor fabrication methods. The future of sensor fabrication technology will be the ink-jet printing method. In this paper, the research developments of flexible carbon heaters and flexible silver IDT electrodes for the time are reported. The characterization of carbon heaters and silver IDT electrodes were carried out and confirmed that the results are favourable for gas sensor applications.
Details
Keywords
Jayaraman Kathirvelan, Rajagopalan Vijayaraghavan and Anna Thomas
The purpose of this paper was to develop a chemo-resistive sensor based on TiO2–WO3 composite material to detect and estimate ethylene released from the fruit ripening process to…
Abstract
Purpose
The purpose of this paper was to develop a chemo-resistive sensor based on TiO2–WO3 composite material to detect and estimate ethylene released from the fruit ripening process to ensure food safety.
Design/methodology/approach
The ethylene sensor has been fabricated using TiO2–WO3 composite material through the sol-gel method.
Findings
The sensitivity of the sensor obtained using the pre-calibrated ethylene is found to be 46.2 per cent at 200 ppm ethylene concentration, and the proposed sensor could measure 8 ppm as the lowest concentration.
Originality/value
The sensor was tested for continuous ethylene detection during natural ripening of fruits and hence is useful for ensuring food safety through discrimination of the type of fruit ripening. A TiO2–WO3 composite ethylene sensor is developed for the first time.
Details
Keywords
Jinyi Li, Zhenhui Du, Zheyuan Zhang, Limei Song and Qinghua Guo
This paper aims to provide a sensor for fast, sensitive and selective ethylene (C2H4) concentration measurements.
Abstract
Purpose
This paper aims to provide a sensor for fast, sensitive and selective ethylene (C2H4) concentration measurements.
Design/methodology/approach
The paper developed a sensor platform based on tunable laser absorption spectroscopy with a 3,266-nm interband cascade laser (ICL) as an optical source and a hollow waveguide (HWG) as a gas cell. The ICL wavelength was scanned across a C2H4 strong fundamental absorption band, and an interference-free C2H4 absorption line located at 3,060.76 cm−1 was selected. Wavelength modulation spectroscopy with the second harmonic detection (WMS-2f) technique was used to improve the sensitivity. Furthermore, the HWG gas cell can achieve a long optical path in a very small volume to improve the time response.
Findings
The results show excellent linearity of the measured 2f signal and the C2H4 concentration with a correlation coefficient of 0.9997. Also, the response time is as short as about 10 s. The Allan variance analysis indicates that the detection limit can achieve 53 ppb with an integration time of 24 s.
Practical implications
The ethylene sensor has many meaningful applications in environmental monitoring, industrial production, national security and the biomedicine field.
Originality/value
The paper provides a novel sensor architecture which can be a versatile sensor platform for fast and sensitive trace-gas detection in the mid-infrared region.
Details
Keywords
Nacira Mecheri, Messaoud Benounis and Houcine Barhoumi
This work aims to determine iron (III) in real water by using a new amperometric sensor on the basis of polyethylene glycol (PEG) to test and characterize a new modified selective…
Abstract
Purpose
This work aims to determine iron (III) in real water by using a new amperometric sensor on the basis of polyethylene glycol (PEG) to test and characterize a new modified selective platinum electrode.
Design/methodology/approach
In this review, the authors focus on testing and characterizing several polymeric membranes by using cyclic voltammetry and square-wave voltammetry (SWV) methods to differentiate the nature of plasticizers (2-Nitrophenyl octyl ether [NPOE], Di-n-octyl phthalate, Bis (2-ethylhexyl) sebacate, PEG. The authors have evaluated the possibility of using crown ether and three zeolite ionophore (faujasite [FAU], Chabazite and ZSM-5) matrixes as novel materials for the selective determination of iron (III) using SWV for the best membranes.
Findings
The results demonstrated that the modified platinum electrode presents linear dependence of amperometric signal with a wide linear range of 10−9 to 10−4 mol.L−1 for iron determination, revealing a detection limit of 10−10 mol.L−1 and amperometric sensibility of 58.58 µA/mol.L−1. The slope of the membrane plasticized with PEG calibration curve is six times higher than that of the other membranes. It was noticed that when the crown ether and the three zeolite ionophores were used, as a new detective material for iron with the membrane plasticized with PEG, the expected results were highly proven. The modified platinum electrode showed high selectivity to iron (III) when the heavy metal ions such as Ni (II), Al (III), Zn (III), Cd (II), Gd (II) and Cu (II) were present.
Originality/value
The utility of the method and the efficiency of the best membrane sensor have been accurately tested by the determination of iron in real water samples of Hassi Messaoud, south of Algeria.
Details
Keywords
Xingxing Li, Shixi You, Zengchang Fan, Guangjun Li and Li Fu
This review provides an overview of recent advances in electrochemical sensors for analyte detection in saliva, highlighting their potential applications in diagnostics and health…
Abstract
Purpose
This review provides an overview of recent advances in electrochemical sensors for analyte detection in saliva, highlighting their potential applications in diagnostics and health care. The purpose of this paper is to summarize the current state of the field, identify challenges and limitations and discuss future prospects for the development of saliva-based electrochemical sensors.
Design/methodology/approach
The paper reviews relevant literature and research articles to examine the latest developments in electrochemical sensing technologies for saliva analysis. It explores the use of various electrode materials, including carbon nanomaterial, metal nanoparticles and conducting polymers, as well as the integration of microfluidics, lab-on-a-chip (LOC) devices and wearable/implantable technologies. The design and fabrication methodologies used in these sensors are discussed, along with sample preparation techniques and biorecognition elements for enhancing sensor performance.
Findings
Electrochemical sensors for salivary analyte detection have demonstrated excellent potential for noninvasive, rapid and cost-effective diagnostics. Recent advancements have resulted in improved sensor selectivity, stability, sensitivity and compatibility with complex saliva samples. Integration with microfluidics and LOC technologies has shown promise in enhancing sensor efficiency and accuracy. In addition, wearable and implantable sensors enable continuous, real-time monitoring of salivary analytes, opening new avenues for personalized health care and disease management.
Originality/value
This review presents an up-to-date overview of electrochemical sensors for analyte detection in saliva, offering insights into their design, fabrication and performance. It highlights the originality and value of integrating electrochemical sensing with microfluidics, wearable/implantable technologies and point-of-care testing platforms. The review also identifies challenges and limitations, such as interference from other saliva components and the need for improved stability and reproducibility. Future prospects include the development of novel microfluidic devices, advanced materials and user-friendly diagnostic devices to unlock the full potential of saliva-based electrochemical sensing in clinical practice.
Details
Keywords
PART V Organic chemistry textbooks. Twenty textbooks of organic chemistry are considered in this part of the review and the organic sections of the syllabuses of three GCE Boards…
The purpose of this paper is to research the durability of the adhesive‐poly(ethylene terephthalate) film joints.
Abstract
Purpose
The purpose of this paper is to research the durability of the adhesive‐poly(ethylene terephthalate) film joints.
Design/methodology/approach
The adhesive‐poly(ethylene terephthalate) joints are prepared with poly ethylene terephthalate film synthesised from thioglycolic acid, terpene hydrocarbon resin and acetone resolution at room temperature. These joints are characterised by methods of peel strength tests, energy dispersive X‐ray spectroscopy (EDX) and analysis of glass transition temperature (Tg) to examine their durability.
Findings
Peel strength tests and EDX analyses prove that water diffusion in different humidity aging conditions causes similar changes, namely having the time‐temperature equivalence at 45°C for 200, 300, 500 and 600 h, respectively, almost corresponding with those at 55°C for 100, 200, 300 and 400 h, respectively, and at 65°C for 50, 100, 150 and 200 h, respectively. The changes in EDX spectra of adhesive‐poly(ethylene terephthalate) film joints indicate that the rate of water penetration in the adhesive is faster than that in the poly(ethylene terephthalate) film. In humidity aging process, the decline ratio of peel strength of adhesive‐poly(ethylene terephthalate) film joints treated with Co60 irradiation is lower than that treated with acetone washing or chemical treatment.
Originality/value
The paper shows that using EDX for analysis of durability of adhesive film joints is of significance to industrial process.
Details
Keywords
R. Rahman, A.K.M.M. Haque and S. Sumar
Reviews the various physical methods available for the detection ofirradiated foods in the areas of: measuring changes in physicalproperties; luminescent detection; and electron…
Abstract
Reviews the various physical methods available for the detection of irradiated foods in the areas of: measuring changes in physical properties; luminescent detection; and electron spin resonance. Concludes that many of the techniques hold great potential as simple screening methods.