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Nalakurthi NVSR, Abimbola I, Ahmed T, Anton I, Riaz K, Ibrahim Q, Banerjee A, Tiwari A, Gharbia S. Challenges and Opportunities in Calibrating Low-Cost Environmental Sensors. SENSORS (BASEL, SWITZERLAND) 2024; 24:3650. [PMID: 38894441 PMCID: PMC11175279 DOI: 10.3390/s24113650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 05/23/2024] [Accepted: 05/26/2024] [Indexed: 06/21/2024]
Abstract
The use of low-cost environmental sensors has gained significant attention due to their affordability and potential to intensify environmental monitoring networks. These sensors enable real-time monitoring of various environmental parameters, which can help identify pollution hotspots and inform targeted mitigation strategies. Low-cost sensors also facilitate citizen science projects, providing more localized and granular data, and making environmental monitoring more accessible to communities. However, the accuracy and reliability of data generated by these sensors can be a concern, particularly without proper calibration. Calibration is challenging for low-cost sensors due to the variability in sensing materials, transducer designs, and environmental conditions. Therefore, standardized calibration protocols are necessary to ensure the accuracy and reliability of low-cost sensor data. This review article addresses four critical questions related to the calibration and accuracy of low-cost sensors. Firstly, it discusses why low-cost sensors are increasingly being used as an alternative to high-cost sensors. In addition, it discusses self-calibration techniques and how they outperform traditional techniques. Secondly, the review highlights the importance of selectivity and sensitivity of low-cost sensors in generating accurate data. Thirdly, it examines the impact of calibration functions on improved accuracies. Lastly, the review discusses various approaches that can be adopted to improve the accuracy of low-cost sensors, such as incorporating advanced data analysis techniques and enhancing the sensing material and transducer design. The use of reference-grade sensors for calibration and validation can also help improve the accuracy and reliability of low-cost sensor data. In conclusion, low-cost environmental sensors have the potential to revolutionize environmental monitoring, particularly in areas where traditional monitoring methods are not feasible. However, the accuracy and reliability of data generated by these sensors are critical for their successful implementation. Therefore, standardized calibration protocols and innovative approaches to enhance the sensing material and transducer design are necessary to ensure the accuracy and reliability of low-cost sensor data.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Salem Gharbia
- Smart Earth Innovation Hub (Earth-Hub), Atlantic Technological University, F91 YW50 Sligo, Ireland; (N.V.S.R.N.); (I.A.); (T.A.); (I.A.); (K.R.); (Q.I.); (A.B.); (A.T.)
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2
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Shukla S, Vishwakarma C, Sah AN, Ahirwar S, Pandey K, Pradhan A. Smartphone-based fluorescence spectroscopic device for cervical precancer diagnosis: a random forest classification of in vitro data. APPLIED OPTICS 2023; 62:6826-6834. [PMID: 37706817 DOI: 10.1364/ao.496543] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 08/11/2023] [Indexed: 09/15/2023]
Abstract
Cervical cancer can be treated and cured if diagnosed at an early stage. Optical devices, developed on smartphone-based platforms, are being tested for this purpose as they are cost-effective, robust, and field portable, showing good efficiency compared to the existing commercial devices. This study reports on the applicability of a 3D printed smartphone-based spectroscopic device (3D-SSD) for the early diagnosis of cervical cancer. The proposed device has the ability to evaluate intrinsic fluorescence (IF) from the collected polarized fluorescence (PF) and elastic-scattering (ES) spectra from cervical tissue samples of different grades. IF spectra of 30 cervical tissue samples have been analyzed and classified using a combination of principal component analysis (PCA) and random forest (RF)-based multi-class classification algorithm with an overall accuracy above 90%. The usage of smartphone for image collection, spectral data analysis, and display makes this device a potential contender for use in clinics as a regular screening tool.
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3
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Boisvert JS, Loranger S, Kashyap R. Fs laser written volume Raman-Nath grating for integrated spectrometer on smartphone. Sci Rep 2023; 13:13717. [PMID: 37608059 PMCID: PMC10444826 DOI: 10.1038/s41598-023-40909-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 08/18/2023] [Indexed: 08/24/2023] Open
Abstract
In this work we demonstrate the integration of a spectrometer directly into smartphone screen by femtosecond laser inscription of a weak Raman-Nath volume grating either into the Corning Gorilla glass screen layer or in the tempered aluminosilicate glass protector screen placed in front of the phone camera. Outside the thermal accumulation regime, a new writing regime yielding positive refractive index change was found for both glasses which is fluence dependent. The upper-bound threshold for this thermal-accumulation-less writing regime was found for both glasses and were, respectively at a repetition rate less than 150 kHz and 101 kHz for fluence of 8.7 × 106 J/m2 and 1.4 × 107 J/m2. A weak volume Raman-Nath grating of dimension 0.5 by 3 mm and 3 μm pitch was placed in front of a Samsung Galaxy S21 FE cellphone to record the spectrum using the 2nd diffraction order. This spectrometer covers the visible band from 401 to 700 nm with a 0.4 nm/pixel detector resolution and 3 nm optical resolution. It was used to determine the concentration detection limit of Rhodamine 6G in water which was found to be 0.5 mg/L. This proof of concept paves the way to in-the-field absorption spectroscopy for quick information gathering.
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Affiliation(s)
- Jean-Sébastien Boisvert
- Department of Engineering Physics, Ecole Polytechnique Montréal, 2900 Édouard-Montpetit, Montreal, QC, H3T 1J4, Canada.
| | - Sébastien Loranger
- Department of Electrical Engineering, Poly-Grames, Ecole Polytechnique Montréal, 2900 Édouard-Montpetit, Montreal, QC, H3T 1J4, Canada
| | - Raman Kashyap
- Department of Engineering Physics, Ecole Polytechnique Montréal, 2900 Édouard-Montpetit, Montreal, QC, H3T 1J4, Canada
- Department of Electrical Engineering, Poly-Grames, Ecole Polytechnique Montréal, 2900 Édouard-Montpetit, Montreal, QC, H3T 1J4, Canada
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Rocher J, Jimenez JM, Tomas J, Lloret J. Low-Cost Turbidity Sensor to Determine Eutrophication in Water Bodies. SENSORS (BASEL, SWITZERLAND) 2023; 23:3913. [PMID: 37112254 PMCID: PMC10143286 DOI: 10.3390/s23083913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 04/04/2023] [Accepted: 04/05/2023] [Indexed: 06/19/2023]
Abstract
Eutrophication is the excessive growth of algae in water bodies that causes biodiversity loss, reducing water quality and attractiveness to people. This is an important problem in water bodies. In this paper, we propose a low-cost sensor to monitor eutrophication in concentrations between 0 to 200 mg/L and in different mixtures of sediment and algae (0, 20, 40, 60, 80, and 100% algae, the rest are sediment). We use two light sources (infrared and RGB LED) and two photoreceptors at 90° and 180° of the light sources. The system has a microcontroller (M5stacks) that powers the light sources and obtains the signal received by the photoreceptors. In addition, the microcontroller is responsible for sending information and generating alerts. Our results show that the use of infrared light at 90° can determine the turbidity with an error of 7.45% in NTU readings higher than 2.73 NTUs, and the use of infrared light at 180° can measure the solid concentration with an error of 11.40%. According to the determination of the % of algae, the use of a neural network has a precision of 89.3% in the classification, and the determination of the mg/L of algae in water has an error of 17.95%.
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Ibrahim MM, Kelani KM, Ramadan NK, Elzanfaly ES. Smartphone as a Portable Detector for Thin-Layer Chromatographic Determination of Some Gastrointestinal Tract Drugs. ACS OMEGA 2022; 7:23815-23820. [PMID: 35847301 PMCID: PMC9281327 DOI: 10.1021/acsomega.2c02482] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Thin-layer chromatography (TLC) is an effective and simple technique for screening, evaluating, and quantifying low-quality and counterfeit pharmaceutical products. Smartphones have recently been used as accessible, cheap, and portable detectors that can replace more complicated analytical detectors. In this work, we have developed a simple and sensitive TLC method utilizing a smartphone charged-coupled device (CCD) camera not only to verify and quantify some gastrointestinal tract drugs, namely, loperamide hydrochloride (LOP) and bisacodyl (BIS), but also to detect acetaminophen (ACT) as a counterfeit drug. Both drugs (LOP and BIS) were chromatographed separately on a silica gel 60 F254 plate as a stationary phase under previously reported chromatographic conditions, using ethyl acetate:methanol:ammonium hydroxide (24:3:1, by volume) and ethyl acetate:methanol:glacial acetic acid (85:10:5, by volume) as developing systems to determine LOP and BIS, respectively. Universal stains, namely, iodine vapors and vanillin, were used to visualize the spots on the TLC plates to get a visual image using the smartphone camera and a spotlight as an illumination source with no need for a UV illumination source. The spot intensity was calculated using a commercially available smartphone application for quantitative analysis of the studied drugs utilizing ″acetaminophen″ as an example of a counterfeit substance. Rf values were calculated using the recorded images and found to be 0.77, 0.79, and 0.74 for LOP, BIS, and ACT, respectively, providing drug identity. Linear calibration curves using the smartphone-TLC method were obtained between the luminance and the corresponding concentrations over the ranges of 2.00-10.00 μg/mL and 1.00-10.00 μg/mL with limits of detection of 0.57 and 0.10 μg/mL for LOP and BIS, respectively. The suggested method was validated according to the International Conference of Harmonization (ICH) guidelines. The method was then successfully applied for the qualitative and quantitative determination of LOP or BIS as an example for gastrointestinal tract drugs in pure form and in their pharmaceutical dosage formulations. The proposed method is considered as a perfect alternative to traditional reported densitometric methods due to its simplicity, easy application, and inexpensiveness. No previously reported methods utilizing smartphones have been published for the determination of the studied drugs. The developed approach is considered the first TLC method using smartphones for the determination of some gastrointestinal tract drugs in their pure form and in pharmaceutical formulations.
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Affiliation(s)
- Maha Mahmoud Ibrahim
- Analytical
Chemistry Department, Faculty of Pharmacy, Modern University for Technology and Information, 12055 Cairo, Egypt
| | - Khadiga Mohamed Kelani
- Analytical
Chemistry Department, Faculty of Pharmacy, Modern University for Technology and Information, 12055 Cairo, Egypt
- Analytical
Chemistry Department, Faculty of Pharmacy, Cairo University, 11562 Cairo, Egypt
| | - Nesreen Khamis Ramadan
- Analytical
Chemistry Department, Faculty of Pharmacy, Cairo University, 11562 Cairo, Egypt
| | - Eman Saad Elzanfaly
- Analytical
Chemistry Department, Faculty of Pharmacy, Cairo University, 11562 Cairo, Egypt
- Pharmaceutical
Chemistry Department, Faculty of Pharmacy
and Drug Technology-Egyptian Chinese University, 11734 Cairo, Egypt
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Peng B, Guo Y, Ma Y, Zhou M, Zhao Y, Wang J, Fang Y. Smartphone-assisted multiple-mode assay of ascorbic acid using cobalt oxyhydroxide nanoflakes and carbon quantum dots. Microchem J 2022. [DOI: 10.1016/j.microc.2022.107185] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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7
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Wang T, Shen F, Deng H, Cai F, Chen S. Smartphone imaging spectrometer for egg/meat freshness monitoring. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2022; 14:508-517. [PMID: 35050274 DOI: 10.1039/d1ay01726h] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Data transmission between spectroscopy equipment and mobile terminals is critical to realising hand-held field-level monitoring. Currently, on-the-go (OTG) communication technology is a convenient and efficient method of data transmission for mobile devices. However, few people associate spectroscopy equipment with smartphones through the OTG port. This study developed a portable imaging spectrometer with a spectral resolution of approximately 12 nm in the visible-near-infrared band (400-1000 nm). It can be connected to a smartphone through the USB-OTG port to process the spectral signal through the smartphone's system on a chip (SoC). It also displays real-time spectral images of the food samples through the smartphone's screen. Using a support vector machine (SVM) to classify the spectra of the various experimental samples (e.g. eggs and pork), the model prediction accuracy rate is approximately 90%. This further proves the reliability of the proposed smartphone imaging spectrometer for monitoring the freshness of food samples onsite.
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Affiliation(s)
- Tianci Wang
- Mechanical and Electrical Engineering College, School of Biomedical Engineering, Key Laboratory of Biomedical Engineering of Hainan Province, Hainan University, Haikou 570228, China.
| | - Fuzhou Shen
- Mechanical and Electrical Engineering College, School of Biomedical Engineering, Key Laboratory of Biomedical Engineering of Hainan Province, Hainan University, Haikou 570228, China.
| | - Hancheng Deng
- Mechanical and Electrical Engineering College, School of Biomedical Engineering, Key Laboratory of Biomedical Engineering of Hainan Province, Hainan University, Haikou 570228, China.
| | - Fuhong Cai
- Mechanical and Electrical Engineering College, School of Biomedical Engineering, Key Laboratory of Biomedical Engineering of Hainan Province, Hainan University, Haikou 570228, China.
| | - Shufen Chen
- Hainan General Hospital (Hainan Affiliated Hospital of Hainan Medical University), Haikou, Hainan, China
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8
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Scheeline A. Selfie Spectrometry: Why Tablets, Laptops, and Cell Phones Have Not Taken Over Visible Spectrometry. Trends Analyt Chem 2022. [DOI: 10.1016/j.trac.2022.116564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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9
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Rabha D, Biswas S, Hatiboruah D, Das P, Rather MA, Mandal M, Nath P. An affordable, handheld multimodal microscopic system with onboard cell morphology and counting features on a mobile device. Analyst 2022; 147:2859-2869. [DOI: 10.1039/d1an02317a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A simple yet effective, handheld and flexible bright-field and fluorescence microscopic platform on a smartphone with varying optical magnifications is reported for morphological analysis and onboard cell counting features.
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Affiliation(s)
- Diganta Rabha
- Applied Photonics and Nanophotonics Laboratory, Department of Physics, Tezpur University, Sonitpur, Assam-784028, India
| | - Sritam Biswas
- Applied Photonics and Nanophotonics Laboratory, Department of Physics, Tezpur University, Sonitpur, Assam-784028, India
| | - Diganta Hatiboruah
- Applied Photonics and Nanophotonics Laboratory, Department of Physics, Tezpur University, Sonitpur, Assam-784028, India
| | - Priyanka Das
- Applied Photonics and Nanophotonics Laboratory, Department of Physics, Tezpur University, Sonitpur, Assam-784028, India
| | - Muzamil Ahmad Rather
- Department of Molecular Biology and Biotechnology, Tezpur University, Sonitpur, Assam-784028, India
| | - Manabendra Mandal
- Department of Molecular Biology and Biotechnology, Tezpur University, Sonitpur, Assam-784028, India
| | - Pabitra Nath
- Applied Photonics and Nanophotonics Laboratory, Department of Physics, Tezpur University, Sonitpur, Assam-784028, India
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10
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11
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Huang J, Qian R, Gao J, Bing H, Huang Q, Qi L, Song S, Huang J. A novel framework to predict water turbidity using Bayesian modeling. WATER RESEARCH 2021; 202:117406. [PMID: 34273777 DOI: 10.1016/j.watres.2021.117406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 06/12/2021] [Accepted: 06/30/2021] [Indexed: 06/13/2023]
Abstract
High water turbidity in aquatic ecosystems is a global challenge due to its harmful impacts. A cost-effective manner to rapidly and accurately measure water turbidity is thus of particular useful in water management with limited resources. This study developed a novel framework aiming to predict water turbidity in various aquatic ecosystems. The framework predicted water turbidity and quantified the uncertainty of the prediction through Bayesian modeling. To improve model performance, a model-update method was implemented in the framework to update the model structure and parameters once more measured data were available. 120 paired records (an image from smartphone and a measured water turbidity value by standard turbidimeters for each record) were collected from rivers, lakes and ponds across China to evaluate the performance of the developed framework. Our cross-validation results revealed a well prediction of water turbidity with Nash-Sutcliffe efficiency (NS) >0.87 (p<0.001) during the training period and NS>0.73 (p<0.001) during the validation period. The model-update method (in case of more measured data) for the developed Bayesian models in the framework resulted in a decreasing trend of model uncertainty and a stable mode fit. This study demonstrated a high value of the Bayesian-based framework in predicting water turbidity in a robust and easy manner.
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Affiliation(s)
- Jiacong Huang
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, China.
| | - Rui Qian
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, China; College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, China
| | - Junfeng Gao
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, China
| | - Haijian Bing
- Key Laboratory of Mountain Surface Process and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China
| | - Qi Huang
- Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang 330022, China
| | - Lingyan Qi
- Engineering Technology Research Center of Resources Environment and GIS, School of Geography and Tourism, Anhui Normal University, 189 South Jiuhua Road, Wuhu 241003, China
| | - Song Song
- School of Geography and Remote Sensing, Guangzhou University, Guangzhou, China
| | - Jiafang Huang
- Key Laboratory of Humid Sub-Tropical Eco-Geographical Processes (Fujian Normal University), Ministry of Education, Fuzhou 350007, China; School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China
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12
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Gad AG, Fayez YM, Kelani KM, Mahmoud AM. TLC-smartphone in antibiotics determination and low-quality pharmaceuticals detection. RSC Adv 2021; 11:19196-19202. [PMID: 35478607 PMCID: PMC9033552 DOI: 10.1039/d1ra01346g] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 05/18/2021] [Indexed: 01/08/2023] Open
Abstract
Thin layer chromatography (TLC) is a powerful and simple technique for screening and quantifying low quality and counterfeit pharmaceutical products. The detection methods used to detect and quantify separate analytes in TLC ranges from the densitometric method to mass spectrometric or Raman spectroscopic methods. This work describes the development and optimization of a simple and sensitive TLC method utilizing a smartphone CCD camera for verification of both identity and quantity of antibiotics in dosage form, namely ofloxacin and ornidazole. Mixtures of ofloxacin and ornidazole were chromatographed on a silica gel 60 F254 plate as a stationary phase. The optimized mobile phase is n-butanol : methanol : ammonia (8 : 1 : 1.5 by volume). Iodine vapor has been used as a "universal stain" to visualize the spots on the TLC plates in order to obtain a visual image using the smartphone camera and a desk lamp as an illumination source, thus eliminating the need for a UV illumination source. The recorded images were processed to calculate the R f values (R f values for ofloxacin and ornidazole were 0.12 and 0.76, respectively) which provide identity of the drugs while spot intensity was calculated using a commercially available smartphone app and employed for quantitative analysis of the antibiotics and "acetaminophen" as an example of a counterfeit substance. The smartphone TLC method yielded a linearity of ofloxacin and ornidazole in the range of 12.5-62.5 μg/band and 500-1000 μg/band, respectively. The limit of detection was found to be 1.6 μg/spot for ofloxacin and 97.8 μg/spot for ornidazole. The proposed method was compared with the bench top densitometric method for verification using a Camag TLC Scanner 3, the spot areas were scanned at 320 nm. The R f value of ofloxacin and ornidazole was calculated to be 0.12 and 0.76, respectively. The densitometric method yielded a linearity of ofloxacin and ornidazole in the range of 5-40 μg/band and 5-50 μg/band, respectively. The limit of detection was found to be 0.8 μg/spot for ofloxacin and 1.1 μg/spot for ornidazole. The proposed method has been successfully applied for the determination of ofloxacin and ornidazole present in more than one pharmaceutical dosage form and was comparable to the densitometric method.
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Affiliation(s)
- Asmaa G Gad
- Analytical Chemistry Department, Faculty of Pharmacy, Modern University for Technology and Information Cairo Egypt
| | - Yasmin Mohammed Fayez
- Analytical Chemistry Department, Faculty of Pharmacy, Cairo University El-Kasr El-Aini Street 11562 Cairo Egypt
| | - Khadiga M Kelani
- Analytical Chemistry Department, Faculty of Pharmacy, Modern University for Technology and Information Cairo Egypt.,Analytical Chemistry Department, Faculty of Pharmacy, Cairo University El-Kasr El-Aini Street 11562 Cairo Egypt
| | - Amr M Mahmoud
- Analytical Chemistry Department, Faculty of Pharmacy, Cairo University El-Kasr El-Aini Street 11562 Cairo Egypt
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13
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Hatiboruah D, Devi DY, Namsa ND, Nath P. Turbidimetric analysis of growth kinetics of bacteria in the laboratory environment using smartphone. JOURNAL OF BIOPHOTONICS 2020; 13:e201960159. [PMID: 31908121 DOI: 10.1002/jbio.201960159] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 12/04/2019] [Accepted: 12/22/2019] [Indexed: 06/10/2023]
Abstract
For different microbiological and pathological studies, it is often required to monitor the growth of bacteria in a cultured medium in the laboratory environment. UV-VIS spectrophotometer is commonly used to estimate the growth of bacterial cell population by measuring the absorbance at 600 nm over a period of time. Colony-forming unit (CFU) is another approach, which has been routinely performed to estimate the live bacterial cells on semisolid agar plates. Herein, we demonstrate an alternative yet highly reliable sensing platform on a smartphone using which growth kinetics of different bacteria can be reliably monitored. The performance of the proposed smartphone sensor has been compared with the data obtained from OD600 and CFU analysis. A good correlation of bacterial growth rates enumerated based on the proposed smartphone sensor, bench-top spectrophotometer and CFU analysis have been observed under the experimental conditions.
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Affiliation(s)
- Diganta Hatiboruah
- Applied Photonics and Nanophotonics Laboratory, Department of Physics, Tezpur University, Tezpur, India
| | - Damayanti Y Devi
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, India
| | - Nima D Namsa
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, India
| | - Pabitra Nath
- Applied Photonics and Nanophotonics Laboratory, Department of Physics, Tezpur University, Tezpur, India
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14
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Zhu Y, Cao P, Liu S, Zheng Y, Huang C. Development of a New Method for Turbidity Measurement Using Two NIR Digital Cameras. ACS OMEGA 2020; 5:5421-5428. [PMID: 32201833 PMCID: PMC7081420 DOI: 10.1021/acsomega.9b04488] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 02/20/2020] [Indexed: 06/10/2023]
Abstract
This paper proposes a new method of using two NIR digital cameras to measure water turbidity accurately and quickly. A measuring device based on an NIR camera and image processing software is designed. Two NIR cameras collect scattered and transmitted images when the NIR light is passing through the turbid solution. The average RGB values of 400 pixels in the central region of the image are obtained and converted into CIE Lab color space values. The water turbidity was measured by the functional relationship between turbidity and the corresponding color components (R, G, B, L, a, b, and grayscale). The results of comparison with a commercial turbidimeter show that this method has a high accuracy for the determination of standard solution with wider linear range and is consistent with the turbidimeter results for the measurement of real samples, which verifies the feasibility of this method.
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Affiliation(s)
- Yuanyang Zhu
- College
of Computer Science and Technology, Huaibei
Normal University, Huaibei 235000, China
| | - Pingping Cao
- College
of Computer Science and Technology, Huaibei
Normal University, Huaibei 235000, China
| | - Sheng Liu
- College
of Computer Science and Technology, Huaibei
Normal University, Huaibei 235000, China
| | - Ying Zheng
- College
of Computer Science and Technology, Huaibei
Normal University, Huaibei 235000, China
| | - Chaoqun Huang
- Anhui
Province Key Laboratory of Medical Physics and Technology, Center
of Medical Physics and Technology, Hefei
Institutes of Physical Science, Chinese Academy of Science, Hefei 230031, China
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15
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Shi B, Li Y, Wu D, Wu W. A handheld continuous-flow real-time fluorescence qPCR system with a PVC microreactor. Analyst 2020; 145:2767-2773. [PMID: 32095799 DOI: 10.1039/c9an01894h] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The polymerase chain reaction (PCR) has unique advantages of sensitivity, specificity and rapidity in pathogen detection, which makes it at the forefront of academia and application in molecular biology diagnosis. In this study, we proposed a hand-held real-time fluorescence qPCR system, which can be used for the quantitative analysis of nucleic acid molecules. For the first time, we use a PVC microreactor which improved the transmittance of the microreactor and made it easy to collect the fluorescence signal. In order to make it portable, the system adopted a passive syringe for sample injection and integrated temperature control and detection with a lithium battery for power supply. What's more, the fluorescence signal was captured by using a smartphone through an external automatic robotic arm. This real-time qPCR system can detect genomic DNA of the H7N9 avian influenza over four orders of magnitude of concentration from 107 to 104 copies per μL. In addition, it was verified that the fluorescence images obtained by this system were clearer than those obtained by a traditional system (using a PTFE spatial PCR microreactor) with two typical dyes and a probe tested-EvaGreen, SYBR Green and FAM.
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Affiliation(s)
- Bing Shi
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Chinese Academy of Sciences, Changchun, 130033, China. and University of Chinese Academy of Sciences (UCAS), Beijing, 100049, China
| | - Yuanming Li
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Chinese Academy of Sciences, Changchun, 130033, China.
| | - Di Wu
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Chinese Academy of Sciences, Changchun, 130033, China. and University of Chinese Academy of Sciences (UCAS), Beijing, 100049, China
| | - Wenming Wu
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Chinese Academy of Sciences, Changchun, 130033, China.
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16
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Vidal E, Lorenzetti AS, Aguirre MÁ, Canals A, Domini CE. New, inexpensive and simple 3D printable device for nephelometric and fluorimetric determination based on smartphone sensing. RSC Adv 2020; 10:19713-19719. [PMID: 35515453 PMCID: PMC9054129 DOI: 10.1039/d0ra02975k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 05/12/2020] [Indexed: 11/21/2022] Open
Abstract
A new, inexpensive and easy to use 3D printable device was developed for nephelometric and fluorimetric determination. Its applicability was tested for the quantification of quinine in tonic drinks and sulfate in natural water with good analytical accuracy. In this way, sulfate determination was carried out by nephelometry using a red LED, while quinine was determined using a blue LED by fluorimetry. A smartphone camera was used to take the pictures and afterwards transform them into the RGB color space using the software ImageJ by a personal computer. The linear range was 2.0–50.0 mg L−1 for sulfate with a LOD of 0.13 mg L−1, and the corresponding quantification limit (LOQ) was 0.43 mg L−1. The linear range for quinine was from 0.42 to 3.10 mg L−1. The LOD and LOQ were 0.11 mg L−1 and 0.38 mg L−1, respectively. A new, inexpensive and easy to use 3D printable device was developed for nephelometric and fluorimetric determination.![]()
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Affiliation(s)
- Ezequiel Vidal
- INQUISUR
- Departamento de Química
- Universidad Nacional del Sur (UNS)-CONICET
- 8000 Bahía Blanca
- Argentina
| | - Anabela S. Lorenzetti
- INQUISUR
- Departamento de Química
- Universidad Nacional del Sur (UNS)-CONICET
- 8000 Bahía Blanca
- Argentina
| | - Miguel Ángel Aguirre
- Departamento de Química Analítica, Nutrición y Bromatología
- Instituto Universitario de Materiales
- Universidad de Alicante
- 03080 Alicante
- Spain
| | - Antonio Canals
- Departamento de Química Analítica, Nutrición y Bromatología
- Instituto Universitario de Materiales
- Universidad de Alicante
- 03080 Alicante
- Spain
| | - Claudia E. Domini
- INQUISUR
- Departamento de Química
- Universidad Nacional del Sur (UNS)-CONICET
- 8000 Bahía Blanca
- Argentina
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Abstract
Water quality is undergoing significant deterioration due to bacteria, pollutants and other harmful particles, damaging aquatic life and lowering the quality of drinking water. It is, therefore, important to be able to rapidly and accurately measure water quality in a cost-effective manner using e.g., a turbidimeter. Turbidimeters typically use different illumination angles to measure the scattering and transmittance of light through a sample and translate these readings into a measurement based on the standard nephelometric turbidity unit (NTU). Traditional turbidimeters have high sensitivity and specificity, but they are not field-portable and require electricity to operate in field settings. Here we present a field-portable and cost effective turbidimeter that is based on a smartphone. This mobile turbidimeter contains an opto-mechanical attachment coupled to the rear camera of the smartphone, which contains two white light-emitting-diodes to illuminate the water sample, optical fibers to transmit the light collected from the sample to the camera, an external lens for image formation, and diffusers for uniform illumination of the sample. Including the smartphone, this cost-effective device weighs only ~350 g. In our mobile turbidimeter design, we combined two illumination approaches: transmittance, in which the optical fibers were placed directly below the sample cuvette at 180° with respect to the light source, and nephelometry in which the optical fibers were placed on the sides of the sample cuvette at a 90° angle with respect to the to the light source. Images of the end facets of these fiber optic cables were captured using the smart phone and processed using a custom written image processing algorithm to automatically quantify the turbidity of each sample. Using transmittance and nephelometric readings, our mobile turbidimeter achieved accurate measurements over a large dynamic range, from 0.3 NTU to 2000 NTU. The accurate performance of our smartphone-based turbidimeter was also confirmed with various water samples collected in Los Angeles (USA), bacteria spiked water samples, as well as diesel fuel contaminated water samples. Having a detection limit of ~0.3 NTU, this cost-effective smartphone-based turbidimeter can be a useful analytical tool for screening of water quality in resource limited settings.
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Long-Term High-Resolution Sediment and Sea Surface Temperature Spatial Patterns in Arctic Nearshore Waters Retrieved Using 30-Year Landsat Archive Imagery. REMOTE SENSING 2019. [DOI: 10.3390/rs11232791] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The Arctic is directly impacted by climate change. The increase in air temperature drives the thawing of permafrost and an increase in coastal erosion and river discharge. This leads to a greater input of sediment and organic matter into coastal waters, which substantially impacts the ecosystems, the subsistence economy of the local population, and the climate because of the transformation of organic matter into greenhouse gases. Yet, the patterns of sediment dispersal in the nearshore zone are not well known, because ships do not often reach shallow waters and satellite remote sensing is traditionally focused on less dynamic environments. The goal of this study is to use the extensive Landsat archive to investigate sediment dispersal patterns specifically on an exemplary Arctic nearshore environment, where field measurements are often scarce. Multiple Landsat scenes were combined to calculate means of sediment dispersal and sea surface temperature under changing seasonal wind conditions in the nearshore zone of Herschel Island Qikiqtaruk in the western Canadian Arctic since 1982. We use observations in the Landsat red and thermal wavebands, as well as a recently published water turbidity algorithm to relate archive wind data to turbidity and sea surface temperature. We map the spatial patterns of turbidity and water temperature at high spatial resolution in order to resolve transport pathways of water and sediment at the water surface. Our results show that these pathways are clearly related to the prevailing wind conditions, being ESE and NW. During easterly wind conditions, both turbidity and water temperature are significantly higher in the nearshore area. The extent of the Mackenzie River plume and coastal erosion are the main explanatory variables for sediment dispersal and sea surface temperature distributions in the study area. During northwesterly wind conditions, the influence of the Mackenzie River plume is negligible. Our results highlight the potential of high spatial resolution Landsat imagery to detect small-scale hydrodynamic processes, but also show the need to specifically tune optical models for Arctic nearshore environments.
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Rabha D, Sarmah A, Nath P. Design of a 3D printed smartphone microscopic system with enhanced imaging ability for biomedical applications. J Microsc 2019; 276:13-20. [PMID: 31498428 DOI: 10.1111/jmi.12829] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 08/31/2019] [Accepted: 09/04/2019] [Indexed: 01/01/2023]
Abstract
Portable, low-cost smartphone platform microscopic systems have emerged as a potential tool for imaging of various micron and submicron scale particles in recent years (Ozcan; Pirnstill and Coté; Breslauer et al.; Zhu et al.). In most of the reported works, it involves either the use of sophisticated optical set-ups along with a high-end computational tool for postprocessing of the captured images, or it requires a high-end configured smartphone to obtain enhanced imaging of the sample. Present work reports the working of a low-cost, field-portable 520× optical microscope using a smartphone. The proposed smartphone microscopic system has been designed by attaching a 3D printed compact optical set-up to the rear camera of a regular smartphone. By using cloud-based services, an image processing algorithm has been developed which can be accessed anytime through a mobile broadband network. Using this facility, the quality of the captured images can be further enhanced, thus obviating the need for dedicated computational tools for postprocessing of the images. With the designed microscopic system, an optical resolution ∼2 µm has been obtained. Upon postprocessing, the resolution of the captured images can be improved further. It is envisioned that with properly designed optical set-up in 3D printer and by developing an image processing application in the cloud, it is possible to obtain a low-cost, user-friendly, field-portable optical microscope on a regular smartphone that performs at par with that of a laboratory-grade microscope. LAY DESCRIPTION: With the ever-improving features both in hardware and software part, smartphone becomes ubiquitous in the modern civilised society with approximately 8.1 billion cell phone users across the world, and ∼40% of them can be considered as smartphones. This technology is undoubtedly the leading technology of the 21st century. Very recently, various researchers across the globe have utilised different sensing components embedded in the smartphone to convert it into a field-portable low-cost and user-friendly tool which can be used for different sensing and imaging purposes. By using simple optical components such as lens, pinhole, diffuser etc. and the camera of the smartphone, various groups have converted the phone into a microscopic imaging system. Again, by removing the camera lenses of the phone, holography images of microscopic particles by directly casting its shadows on the CMOS sensor on the phone has been demonstrated. The holographic images have subsequently been processed using the dedicated computational tool, and the original photos of the samples can be obtained. All the reported smartphone-based microscopic systems either suffer from relatively low field-of-view (FOV), resolution or it needs a high computational platform. Present work, demonstrate an alternative approach by which a reasonably good resolution (<2 µm) along with high optical magnification (520×) and a large FOV (150 µm) has been obtained on a regular smartphone. For postprocessing of the captured images an image processing algorithm has been developed in the cloud and the same can be accessed by the smartphone application, obviating the need of dedicated computational tool and a high-end configured smartphone for the proposed microscope. For the development of the proposed microscopic system, a simple optical set-up has been fabricated in a 3D printer. The set-up houses all the required optical components and the sample specimen with the 3D-printed XY stage, and it can be attached easily to the rear camera of the smartphone. Using the proposed microscopic system, enhanced imaging of USAF target and red blood cells have been successfully demonstrated. With the readily available optical components and a regular smartphone, the net cost involvement is significantly low (less than $250, including the smartphone). We envisioned that the designed system could be utilised for point-of-care diagnosis in resource-poor settings where access to the laboratory facilities is very limited.
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Affiliation(s)
- D Rabha
- Applied Photonics and Nanophotonics Laboratory, Department of Physics, Tezpur University, Sonitpur, Assam, India
| | - A Sarmah
- Department of Pathology, Tezpur Medical College and Hospital, Sonitpur, Assam, India
| | - P Nath
- Applied Photonics and Nanophotonics Laboratory, Department of Physics, Tezpur University, Sonitpur, Assam, India
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Kim M, Lee J, Nam J. Plasmonic Photothermal Nanoparticles for Biomedical Applications. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2019; 6:1900471. [PMID: 31508273 PMCID: PMC6724476 DOI: 10.1002/advs.201900471] [Citation(s) in RCA: 269] [Impact Index Per Article: 53.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 05/19/2019] [Indexed: 05/02/2023]
Abstract
Recent advances of plasmonic nanoparticles include fascinating developments in the fields of energy, catalyst chemistry, optics, biotechnology, and medicine. The plasmonic photothermal properties of metallic nanoparticles are of enormous interest in biomedical fields because of their strong and tunable optical response and the capability to manipulate the photothermal effect by an external light source. To date, most biomedical applications using photothermal nanoparticles have focused on photothermal therapy; however, to fully realize the potential of these particles for clinical and other applications, the fundamental properties of photothermal nanoparticles need to be better understood and controlled, and the photothermal effect-based diagnosis, treatment, and theranostics should be thoroughly explored. This Progress Report summarizes recent advances in the understanding and applications of plasmonic photothermal nanoparticles, particularly for sensing, imaging, therapy, and drug delivery, and discusses the future directions of these fields.
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Affiliation(s)
- Minho Kim
- Department of ChemistrySeoul National UniversitySeoul08826South Korea
| | - Jung‐Hoon Lee
- Department of ChemistryCity University of Hong KongHong Kong SAR, P. R. China
| | - Jwa‐Min Nam
- Department of ChemistrySeoul National UniversitySeoul08826South Korea
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21
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Rezazadeh M, Seidi S, Lid M, Pedersen-Bjergaard S, Yamini Y. The modern role of smartphones in analytical chemistry. Trends Analyt Chem 2019. [DOI: 10.1016/j.trac.2019.06.019] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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22
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Shang J, Yu L, Sun Y, Chen X, Kang Q, Shen D. On site determination of free chlorine in water samples by a smartphone-based colorimetric device with improved sensitivity and reliability. NEW J CHEM 2019. [DOI: 10.1039/c9nj03954f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Absorbance in a long-path portable colorimetric device was measured by a ratiometric fluorescent strategy in a smartphone platform.
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Affiliation(s)
- Jian Shang
- College of Chemistry
- Chemical Engineering and Materials Science
- Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong
- Shandong Normal University
- Jinan 250014
| | - Lei Yu
- College of Chemistry
- Chemical Engineering and Materials Science
- Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong
- Shandong Normal University
- Jinan 250014
| | - Yan Sun
- College of Chemistry
- Chemical Engineering and Materials Science
- Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong
- Shandong Normal University
- Jinan 250014
| | - Xiaolan Chen
- College of Chemistry
- Chemical Engineering and Materials Science
- Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong
- Shandong Normal University
- Jinan 250014
| | - Qi Kang
- College of Chemistry
- Chemical Engineering and Materials Science
- Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong
- Shandong Normal University
- Jinan 250014
| | - Dazhong Shen
- College of Chemistry
- Chemical Engineering and Materials Science
- Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong
- Shandong Normal University
- Jinan 250014
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23
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Dutta S. Point of care sensing and biosensing using ambient light sensor of smartphone: Critical review. Trends Analyt Chem 2019. [DOI: 10.1016/j.trac.2018.11.014] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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24
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Hussain I, Nath P. Design of a 3D printed compact interferometric system and required phone application for small angular measurements. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:103111. [PMID: 30399881 DOI: 10.1063/1.5040189] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 10/06/2018] [Indexed: 06/08/2023]
Abstract
A 3D printed smartphone based interferometric system is proposed, and its usability has been demonstrated by measuring small angular rotations. All necessary fringe processing and data analysis have been performed within the phone itself using custom designed application developed in an android platform. The main objective of the proposed work is to demonstrate the usability of modern smartphone and 3D printing technology for optical interferometric applications. The smartphone camera has been used to record the interference fringes which has been formed due to the change in the optical path difference (OPD) between light rays reflected from the top and bottom surface of a microscopic glass slide. The angular variation of the slide causes a detectable change in the OPD between the interfering beams which subsequently would cause a variation in the fringe pattern. By evaluating necessary interferometric parameters, small angular rotation can be computed within the smartphone application. With the designed smartphone based interferometric system, angular rotation as small as 0.02° can be measured accurately and reliably having a dynamic range of -3.68° to 3.68°. Due to the involvement of the smartphone as a platform for recording as well as onboard fringe processing, the designed interferometric system can be visualized as a truly field portable tool for different optical metrological applications.
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Affiliation(s)
- I Hussain
- Applied Photonics and Nanophotonics Laboratory, Department of Physics, Tezpur University, Nappam 78402, India
| | - P Nath
- Applied Photonics and Nanophotonics Laboratory, Department of Physics, Tezpur University, Nappam 78402, India
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Bayram A, Yalcin E, Demic S, Gunduz O, Solmaz ME. Development and application of a low-cost smartphone-based turbidimeter using scattered light. APPLIED OPTICS 2018; 57:5935-5940. [PMID: 30118016 DOI: 10.1364/ao.57.005935] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 06/10/2018] [Indexed: 06/08/2023]
Abstract
We demonstrate the development and application of a low-cost smartphone turbidimeter system to be used on water samples collected from natural resources. The proposed system depends on the spectroscopic measurements of both forward- and side-scattered light. A custom-designed cradle was fabricated using 3D printing, and plastic optical fibers were used to couple light from the smartphone's built-in flash and transmit the collected scattered light to the camera sensor. The performance parameters of the smartphone turbidimeter were investigated and compared to commercial systems, and the lowest limit of detection was found to be 5.58 NTU for forward-scattered detection. The results obtained in the proposed scattered-light-based spectroscopic turbidimeter and the practicality achieved by this extremely low-cost device will have a great impact on water science and technology.
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26
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Metzger M, Konrad A, Blendinger F, Modler A, Meixner AJ, Bucher V, Brecht M. Low-Cost GRIN-Lens-Based Nephelometric Turbidity Sensing in the Range of 0.1-1000 NTU. SENSORS 2018; 18:s18041115. [PMID: 29642380 PMCID: PMC5948488 DOI: 10.3390/s18041115] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 03/28/2018] [Accepted: 04/04/2018] [Indexed: 11/16/2022]
Abstract
Turbidity sensing is very common in the control of drinking water. Furthermore, turbidity measurements are applied in the chemical (e.g., process monitoring), pharmaceutical (e.g., drug discovery), and food industries (e.g., the filtration of wine and beer). The most common measurement technique is nephelometric turbidimetry. A nephelometer is a device for measuring the amount of scattered light of suspended particles in a liquid by using a light source and a light detector orientated in 90° to each other. Commercially available nephelometers cost usually-depending on the measurable range, reliability, and precision-thousands of euros. In contrast, our new developed GRIN-lens-based nephelometer, called GRINephy, combines low costs with excellent reproducibility and precision, even at very low turbidity levels, which is achieved by its ability to rotate the sample. Thereby, many cuvette positions can be measured, which results in a more precise average value for the turbidity calculated by an algorithm, which also eliminates errors caused by scratches and contaminations on the cuvettes. With our compact and cheap Arduino-based sensor, we are able to measure in the range of 0.1-1000 NTU and confirm the ISO 7027-1:2016 for low turbidity values.
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Affiliation(s)
- Michael Metzger
- Institute for Applied Research, Faculty for Mechanical and Medical Engineering, Furtwangen University, 78054 Villingen-Schwenningen, Germany.
- Institute of Physical and Theoretical Chemistry, University of Tuebingen, 72076 Tuebingen, Germany.
| | - Alexander Konrad
- Institute of Physical and Theoretical Chemistry, University of Tuebingen, 72076 Tuebingen, Germany.
| | - Felix Blendinger
- Institute for Applied Research, Faculty for Mechanical and Medical Engineering, Furtwangen University, 78054 Villingen-Schwenningen, Germany.
| | - Andreas Modler
- Department of Mathematics, Physics and Chemistry, Beuth University of Applied Sciences, 13353 Berlin, Germany.
| | - Alfred J Meixner
- Institute of Physical and Theoretical Chemistry, University of Tuebingen, 72076 Tuebingen, Germany.
| | - Volker Bucher
- Institute for Applied Research, Faculty for Mechanical and Medical Engineering, Furtwangen University, 78054 Villingen-Schwenningen, Germany.
| | - Marc Brecht
- Institute of Physical and Theoretical Chemistry, University of Tuebingen, 72076 Tuebingen, Germany.
- Process Analysis and Technology (PA&T), Reutlingen Research Institute, Reutlingen University, 72762 Reutlingen, Germany.
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Igoe DP, Parisi AV, Amar A, Rummenie KJ. Median filters as a tool to determine dark noise thresholds in high resolution smartphone image sensors for scientific imaging. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:015003. [PMID: 29390698 DOI: 10.1063/1.5006000] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
An evaluation of the use of median filters in the reduction of dark noise in smartphone high resolution image sensors is presented. The Sony Xperia Z1 employed has a maximum image sensor resolution of 20.7 Mpixels, with each pixel having a side length of just over 1 μm. Due to the large number of photosites, this provides an image sensor with very high sensitivity but also makes them prone to noise effects such as hot-pixels. Similar to earlier research with older models of smartphone, no appreciable temperature effects were observed in the overall average pixel values for images taken in ambient temperatures between 5 °C and 25 °C. In this research, hot-pixels are defined as pixels with intensities above a specific threshold. The threshold is determined using the distribution of pixel values of a set of images with uniform statistical properties associated with the application of median-filters of increasing size. An image with uniform statistics was employed as a training set from 124 dark images, and the threshold was determined to be 9 digital numbers (DN). The threshold remained constant for multiple resolutions and did not appreciably change even after a year of extensive field use and exposure to solar ultraviolet radiation. Although the temperature effects' uniformity masked an increase in hot-pixel occurrences, the total number of occurrences represented less than 0.1% of the total image. Hot-pixels were removed by applying a median filter, with an optimum filter size of 7 × 7; similar trends were observed for four additional smartphone image sensors used for validation. Hot-pixels were also reduced by decreasing image resolution. The method outlined in this research provides a methodology to characterise the dark noise behavior of high resolution image sensors for use in scientific investigations, especially as pixel sizes decrease.
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Affiliation(s)
- Damien P Igoe
- Faculty of Health, Engineering and Sciences, University of Southern Queensland, Toowoomba, Australia
| | - Alfio V Parisi
- Faculty of Health, Engineering and Sciences, University of Southern Queensland, Toowoomba, Australia
| | - Abdurazaq Amar
- Faculty of Health, Engineering and Sciences, University of Southern Queensland, Toowoomba, Australia
| | - Katherine J Rummenie
- Faculty of Health, Engineering and Sciences, University of Southern Queensland, Toowoomba, Australia
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Geng Z, Zhang X, Fan Z, Lv X, Su Y, Chen H. Recent Progress in Optical Biosensors Based on Smartphone Platforms. SENSORS 2017; 17:s17112449. [PMID: 29068375 PMCID: PMC5713127 DOI: 10.3390/s17112449] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 10/19/2017] [Accepted: 10/20/2017] [Indexed: 02/07/2023]
Abstract
With a rapid improvement of smartphone hardware and software, especially complementary metal oxide semiconductor (CMOS) cameras, many optical biosensors based on smartphone platforms have been presented, which have pushed the development of the point-of-care testing (POCT). Imaging-based and spectrometry-based detection techniques have been widely explored via different approaches. Combined with the smartphone, imaging-based and spectrometry-based methods are currently used to investigate a wide range of molecular properties in chemical and biological science for biosensing and diagnostics. Imaging techniques based on smartphone-based microscopes are utilized to capture microscale analysts, while spectrometry-based techniques are used to probe reactions or changes of molecules. Here, we critically review the most recent progress in imaging-based and spectrometry-based smartphone-integrated platforms that have been developed for chemical experiments and biological diagnosis. We focus on the analytical performance and the complexity for implementation of the platforms.
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Affiliation(s)
- Zhaoxin Geng
- School of Information Engineering, Minzu University of China, Beijing 100081, China.
| | - Xiong Zhang
- School of Information Engineering, Minzu University of China, Beijing 100081, China.
| | - Zhiyuan Fan
- State Key Laboratory for Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
| | - Xiaoqing Lv
- State Key Laboratory for Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
| | - Yue Su
- State Key Laboratory for Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
| | - Hongda Chen
- State Key Laboratory for Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
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29
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Zarei M. Portable biosensing devices for point-of-care diagnostics: Recent developments and applications. Trends Analyt Chem 2017. [DOI: 10.1016/j.trac.2017.04.001] [Citation(s) in RCA: 195] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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30
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Dutta S, Saikia GP, Sarma DJ, Gupta K, Das P, Nath P. Protein, enzyme and carbohydrate quantification using smartphone through colorimetric digitization technique. JOURNAL OF BIOPHOTONICS 2017; 10:623-633. [PMID: 27243385 DOI: 10.1002/jbio.201500329] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 05/02/2016] [Accepted: 05/04/2016] [Indexed: 06/05/2023]
Abstract
In this paper the utilization of smartphone as a detection platform for colorimetric quantification of biological macromolecules has been demonstrated. Using V-channel of HSV color space, the quantification of BSA protein, catalase enzyme and carbohydrate (using D-glucose) have been successfully investigated. A custom designed android application has been developed for estimating the total concentration of biological macromolecules. The results have been compared with that of a standard spectrophotometer which is generally used for colorimetric quantification in laboratory settings by measuring its absorbance at a specific wavelength. The results obtained with the designed sensor is found to be similar when compared with the spectrophotometer data. The designed sensor is low cost, robust and we envision that it could promote diverse fields of bio-analytical investigations. Schematic illustration of the smartphone sensing mechanism for colorimetric analysis of biomolecular samples.
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Affiliation(s)
- Sibasish Dutta
- Applied Photonics and Nanophotonics Laboratory, Department of Physics, Tezpur University, Napaam, Assam, 784028, India
| | - Gunjan Prasad Saikia
- Department of Computer science, Guwahati University, Gopinath Bordoloi Nagar, Guwahati, Assam, 781014, India
| | - Dhruva Jyoti Sarma
- Applied Biochemistry Laboratory, Department of Molecular Biology and Biotechnology, Tezpur University, Napaam, Assam, 784028, India
| | - Kuldeep Gupta
- Applied Microbiology and Biotechnology Laboratory, Department of Molecular Biology and Biotechnology, Tezpur University, Napaam, Assam, 784028, India
| | - Priyanka Das
- Applied Photonics and Nanophotonics Laboratory, Department of Physics, Tezpur University, Napaam, Assam, 784028, India
| | - Pabitra Nath
- Applied Photonics and Nanophotonics Laboratory, Department of Physics, Tezpur University, Napaam, Assam, 784028, India
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31
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Hussain I, Ahamad KU, Nath P. Low-Cost, Robust, and Field Portable Smartphone Platform Photometric Sensor for Fluoride Level Detection in Drinking Water. Anal Chem 2016; 89:767-775. [PMID: 27982569 DOI: 10.1021/acs.analchem.6b03424] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Groundwater is the major source of drinking water for people living in rural areas of India. Pollutants such as fluoride in groundwater may be present in much higher concentration than the permissible limit. Fluoride does not give any visible coloration to water, and hence, no effort is made to remove or reduce the concentration of this chemical present in drinking water. This may lead to a serious health hazard for those people taking groundwater as their primary source of drinking water. Sophisticated laboratory grade tools such as ion selective electrodes (ISE) and portable spectrophotometers are commercially available for in-field detection of fluoride level in drinking water. However, such tools are generally expensive and require expertise to handle. In this paper, we demonstrate the working of a low cost, robust, and field portable smartphone platform fluoride sensor that can detect and analyze fluoride concentration level in drinking water. For development of the proposed sensor, we utilize the ambient light sensor (ALS) of the smartphone as light intensity detector and its LED flash light as an optical source. An android application "FSense" has been developed which can detect and analyze the fluoride concentration level in water samples. The custom developed application can be used for sharing of in-field sensing data from any remote location to the central water quality monitoring station. We envision that the proposed sensing technique could be useful for initiating a fluoride removal program undertaken by governmental and nongovernmental organizations here in India.
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Affiliation(s)
- Iftak Hussain
- Applied Photonics and Nano-Photonics Laboratory, Department of Physics, and ‡Department of Civil Engineering, Tezpur University , Assam 784028, India
| | - Kamal Uddin Ahamad
- Applied Photonics and Nano-Photonics Laboratory, Department of Physics, and ‡Department of Civil Engineering, Tezpur University , Assam 784028, India
| | - Pabitra Nath
- Applied Photonics and Nano-Photonics Laboratory, Department of Physics, and ‡Department of Civil Engineering, Tezpur University , Assam 784028, India
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