1
|
Pastore A, Badocco D, Cappellin L, Tubiana M, Zanut A, Bogialli S, Roverso M, Pastore P. Accurate pH Monitoring of Highly Concentrated Saline Aqueous Solutions (Seawater-like) with a pH Colorimetric Sensor Array. ACS Sens 2024; 9:1482-1488. [PMID: 38416572 DOI: 10.1021/acssensors.3c02585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2024]
Abstract
A pH colorimetric sensor array (CSA) was prepared on a nitrocellulose membrane and used for accurate pH measurement in highly concentrated saline solutions. The CSAs consisted of sensing spots made of a suitable OrMoSil polymer prepared from organo-fluorinated-silane precursors and/or organosilane with tetraethyl orthosilicate hosting an acid-base indicator. Four CSAs were prepared: D, 1F, 2F, and 3F. In D, a nonfluorinated organosilane was present. From 1F to 3F, the concentration of the fluorinated organosilane increased and improved the pH measurement accuracy in highly saline concentrations. No recalibrations were required, and the analytical signal was stable in time. D, 1F, 2F, and 3F were deposited in triplicate, and they were prepared to work in the seawater pH interval (7.50-8.50). The use of fluorinated precursors led to a lower pH prediction error and tailored the interval of the CSA at more basic pH values so that the inflection points of the sigmoidal calibrations of D, 1F, 2F, and 3F moved from 6.97 to 7.98. The overall pH prediction error was 0.10 pH (1F), 0.02 pH (2F), and 0.04 pH units (3F). The CSAs were stable, reversible, reusable, and independent of salinity (S) between 20 and 40. The performances of the CSA were compared with those of a glass electrode, whose pHNIST values were converted in the pHSWS scale through a conversion equation. Being unaffected by the typical drawback of the glass electrode, the CSAs can be used directly in seawater real samples, and it validated the proposed conversion equation.
Collapse
Affiliation(s)
- Andrea Pastore
- Department of Chemical Sciences, University of Padua, Via Marzolo 1, 35131 Padua, Italy
| | - Denis Badocco
- Department of Chemical Sciences, University of Padua, Via Marzolo 1, 35131 Padua, Italy
| | - Luca Cappellin
- Department of Chemical Sciences, University of Padua, Via Marzolo 1, 35131 Padua, Italy
| | - Mauro Tubiana
- Department of Chemical Sciences, University of Padua, Via Marzolo 1, 35131 Padua, Italy
| | - Alessandra Zanut
- Department of Chemical Sciences, University of Padua, Via Marzolo 1, 35131 Padua, Italy
| | - Sara Bogialli
- Department of Chemical Sciences, University of Padua, Via Marzolo 1, 35131 Padua, Italy
| | - Marco Roverso
- Department of Chemical Sciences, University of Padua, Via Marzolo 1, 35131 Padua, Italy
| | - Paolo Pastore
- Department of Chemical Sciences, University of Padua, Via Marzolo 1, 35131 Padua, Italy
| |
Collapse
|
2
|
Pastore A, Badocco D, Cappellin L, Tubiana M, Pastore P. Positively Charged Organosilanes Covalently Linked to the Silica Network as Modulating Tools for the Salinity Correction of pH Values Obtained with Colorimetric Sensor Arrays (CSAs). SENSORS (BASEL, SWITZERLAND) 2024; 24:417. [PMID: 38257510 PMCID: PMC10818285 DOI: 10.3390/s24020417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 12/30/2023] [Accepted: 01/03/2024] [Indexed: 01/24/2024]
Abstract
Seven increasing levels of water salinity from 0.029 to 0.600 M (as NaCl) were used to investigate the dependence of pH measurement, performed using colorimetric sensor arrays (CSAs), on ionic strength. The CSAs were arrays of sensing spots prepared in the form of sol-gel-embedding Bromothymol Blue (BB) and Bromocresol Green (BCG) in a porous nitrocellulose support. The support was impregnated over the entire thickness (≈100 µm), allowing for the signal (Hue) acquisition on the opposite side to the contact with the sample solution. Three CSAs were prepared, M1, M2, and M3. M1 contained a free cationic surfactant, hexadecyltrimethylammonium p-toluenesulfonate (CTApTs), for modulating the pKa of the indicators. In M2, the surfactant dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (DTSACl) was covalently bonded to the sol-gel. M3 was prepared like M2 but using a larger amount of ethanol as the solvent for the synthesis. The modulation of the CTApTs or the DTSACl concentration enabled the tuning of the pKa. In general, the pKa modulation ability decreased with the increase in salinity. The presence of a surfactant covalently linked to the backbone partially reduced the competitiveness of the anionic species, improving the results. Nevertheless, the salt effect was still present, and a correction algorithm was required. Between pH 5.00 and 12.00, this correction could be made automatically by using spots taken as references to produce sensors independent of salinity. As the salt effect is virtually absent above 0.160 M, M2 and M3 can be used for future applications in seawater.
Collapse
Affiliation(s)
| | | | | | | | - Paolo Pastore
- Department of Chemical Sciences, University of Padua, Via Marzolo 1, 35131 Padua, Italy; (A.P.); (D.B.); (L.C.); (M.T.)
| |
Collapse
|
3
|
Wang F, Zhang X, Huangfu C, Zhi H, Wang Y, Feng L. Novel Paraquat Detection Strategy Enabled by Carboxylatopillar[5]arene Confined in Nanochannels on a Paper-Based Sensor. Anal Chem 2022; 94:18059-18066. [PMID: 36523210 DOI: 10.1021/acs.analchem.2c04586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Paper-based optical sensors have emerged as a promising technology for pesticide detection and attracted extensive attention. However, in practical analytical applications, it may suffer from limited sensitivity with traditional signal amplification strategies. Here, we developed a novel mesoporous silica-modified paper-based sensor for a sensitive capture and analysis of the pesticide paraquat. Carboxylatopillar[5]arene was covalently introduced into the nanochannels for the rapid capture of target paraquat molecules due to the mass transfer confinement effect within nanopores. In addition, the large specific surface area of mesoporous silica enabled high-abundance immobilization of the capture agent and promoted its binding efficiency, which, in turn, contributed to improving the sensitivity. This work highlights the great potential of nanochannels as a development platform for sensitive paper-based sensors that can be used to develop new systems for the detection of paraquat and even other pesticides.
Collapse
Affiliation(s)
- Fengya Wang
- Department of Instrumentation and Analytical Chemistry, CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian116023, P. R. China.,University of Chinese Academy of Sciences, Beijing100049, P. R. China
| | - Xiaobo Zhang
- Department of Instrumentation and Analytical Chemistry, CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian116023, P. R. China.,University of Chinese Academy of Sciences, Beijing100049, P. R. China
| | - Changxin Huangfu
- Department of Instrumentation and Analytical Chemistry, CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian116023, P. R. China
| | - Hui Zhi
- Department of Instrumentation and Analytical Chemistry, CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian116023, P. R. China
| | - Yu Wang
- Department of Instrumentation and Analytical Chemistry, CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian116023, P. R. China
| | - Liang Feng
- Department of Instrumentation and Analytical Chemistry, CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian116023, P. R. China
| |
Collapse
|
4
|
Melnikov P, Bobrov A, Marfin Y. On the Use of Polymer-Based Composites for the Creation of Optical Sensors: A Review. Polymers (Basel) 2022; 14:polym14204448. [PMID: 36298026 PMCID: PMC9611646 DOI: 10.3390/polym14204448] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/08/2022] [Accepted: 10/17/2022] [Indexed: 11/16/2022] Open
Abstract
Polymers are widely used in many areas, but often their individual properties are not sufficient for use in certain applications. One of the solutions is the creation of polymer-based composites and nanocomposites. In such materials, in order to improve their properties, nanoscale particles (at least in one dimension) are dispersed in the polymer matrix. These properties include increased mechanical strength and durability, the ability to create a developed inner surface, adjustable thermal and electrical conductivity, and many others. The materials created can have a wide range of applications, such as biomimetic materials and technologies, smart materials, renewable energy sources, packaging, etc. This article reviews the usage of composites as a matrix for the optical sensors and biosensors. It highlights several methods that have been used to enhance performance and properties by optimizing the filler. It shows the main methods of combining indicator dyes with the material of the sensor matrix. Furthermore, the role of co-fillers or a hybrid filler in a polymer composite system is discussed, revealing the great potential and prospect of such matrixes in the field of fine properties tuning for advanced applications.
Collapse
Affiliation(s)
- Pavel Melnikov
- M. V. Lomonosov Institute of Fine Chemical Technologies, MIREA—Russian Technological University, 119571 Moscow, Russia
- Correspondence:
| | - Alexander Bobrov
- Department of Inorganic Chemistry, Ivanovo State University of Chemistry and Technology, Sheremetevsky pr., 10, 153010 Ivanovo, Russia
| | - Yuriy Marfin
- Department of Inorganic Chemistry, Ivanovo State University of Chemistry and Technology, Sheremetevsky pr., 10, 153010 Ivanovo, Russia
- Pacific National University, 136 Tikhookeanskaya Street, 680035 Khabarovsk, Russia
| |
Collapse
|
5
|
Wang L, Jensen K, Hatzakis N, Zhang M, Sørensen TJ. Robust Dual Optical Sensor for pH and Dissolved Oxygen. ACS Sens 2022; 7:1506-1513. [PMID: 35535664 DOI: 10.1021/acssensors.2c00242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
As part of moving our optical pH and dissolved oxygen (DO) optical chemosensors toward industrial applications, we decided to explore a many-sensors-in-one principle. It was tested if physical segregation of the optical sensor components in a single sensor polymer could remove cross-talk and quenching. It was found that a design concept with an oxygen-responsive dye in polymer nanoparticles and a pH-responsive dye in an organically modified siloxane polymer resulted in a robust pH/O2 dual optical sensor. Individually, the O2-sensitive nanoparticles, a known component for optical DO sensing, and the pH sensor are operational. Thus, it was decided to test if nanoparticles enclosed within the pH-sensitive responsive sol-gel (i) could work together if segregated and (ii) could operate with a single intensity signal that is without a reference signal; developments within industrial optical sensor technology indicate that this should be feasible. The prototype optode produced in this work was shown to have a negligible drift over 60 h, bulk diffusion-limited DO response, and independent response to pH and O2. On the individual optode, pH calibration was found to show the expected sigmoidal shape and pKa, while the complexity of the calibration function for the DO signal was significant. While the engineering of the sensor device, optics, and hardware are not robust enough to attempt generic sensor calibration, it was decided to demonstrate the design concept in simple fermentation experiments. We conclude that the dual sensor design with the physical segregation of components is viable.
Collapse
Affiliation(s)
- Lu Wang
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
| | - Kim Jensen
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
| | - Nikos Hatzakis
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Min Zhang
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Thomas Just Sørensen
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
| |
Collapse
|
6
|
Huynh GT, Henderson EC, Frith JE, Meagher L, Corrie SR. Stability and Performance Study of Fluorescent Organosilica pH Nanosensors. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:6578-6587. [PMID: 34009994 DOI: 10.1021/acs.langmuir.1c00936] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Long-term stability and function are key challenges for optical nanosensors operating in complex biological environments. While much focus is rightly placed on issues related to specificity, sensitivity, reversibility, and response time, many nanosensors are not capable of transducing accurate results over prolonged time periods. Sensors could fail over time due to the degradation of scaffold material, degradation of signaling dyes and components, or a combination of both. It is critical to investigate how such degradative processes affect sensor output, as the consequences could be severe. Herein, we used fluorescent core-shell organosilica pH nanosensors as a model system, incubating them in a range of common aqueous solutions over time at different temperatures, and then searched for changes in fluorescence signal, particle size, and evidence of silica degradation. We found that these ratiometric nanosensors produced stable optical signals after aging for 30 days at 37 °C in standard saline buffers with and without 10% fetal bovine serum, and without any evidence of material degradation. Next, we evaluated their performance as real-time pH nanosensors in bacterial suspension cultures, observing a close agreement with a pH electrode for control nanosensors, yet observing obvious deviations in signal based on the aging conditions. The results show that while the organosilica scaffold does not degrade appreciably over time, careful selection of dyes and further systematic investigations into the effects of salt and protein levels are required to realize long-term stable nanosensors.
Collapse
Affiliation(s)
- Gabriel T Huynh
- Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Node, Clayton, VIC 3800, Australia
| | - Edward C Henderson
- Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Node, Clayton, VIC 3800, Australia
| | - Jessica E Frith
- Monash Institute of Medical Engineering, Monash University, Clayton, VIC 3800, Australia
- Department of Material Science and Engineering, Monash University, Clayton, VIC 3800, Australia
- ARC Training Centre for Cell and Tissue Engineering Technologies, Monash University, Clayton, VIC 3800, Australia
| | - Laurence Meagher
- Department of Material Science and Engineering, Monash University, Clayton, VIC 3800, Australia
- ARC Training Centre for Cell and Tissue Engineering Technologies, Monash University, Clayton, VIC 3800, Australia
| | - Simon R Corrie
- Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Node, Clayton, VIC 3800, Australia
- ARC Training Centre for Cell and Tissue Engineering Technologies, Monash University, Clayton, VIC 3800, Australia
| |
Collapse
|
7
|
pH measurement and phosphate determination in pharmaceutical eye drops for eye diseases by digital image analysis. Microchem J 2021. [DOI: 10.1016/j.microc.2020.105854] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
8
|
Pastore A, Badocco D, Bogialli S, Cappellin L, Pastore P. Behavior of Sulfonephthalein and Azo dyes as effective pH sensors in hybrid materials. Microchem J 2021. [DOI: 10.1016/j.microc.2020.105605] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
9
|
Steinegger A, Wolfbeis OS, Borisov SM. Optical Sensing and Imaging of pH Values: Spectroscopies, Materials, and Applications. Chem Rev 2020; 120:12357-12489. [PMID: 33147405 PMCID: PMC7705895 DOI: 10.1021/acs.chemrev.0c00451] [Citation(s) in RCA: 182] [Impact Index Per Article: 45.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Indexed: 12/13/2022]
Abstract
This is the first comprehensive review on methods and materials for use in optical sensing of pH values and on applications of such sensors. The Review starts with an introduction that contains subsections on the definition of the pH value, a brief look back on optical methods for sensing of pH, on the effects of ionic strength on pH values and pKa values, on the selectivity, sensitivity, precision, dynamic ranges, and temperature dependence of such sensors. Commonly used optical sensing schemes are covered in a next main chapter, with subsections on methods based on absorptiometry, reflectometry, luminescence, refractive index, surface plasmon resonance, photonic crystals, turbidity, mechanical displacement, interferometry, and solvatochromism. This is followed by sections on absorptiometric and luminescent molecular probes for use pH in sensors. Further large sections cover polymeric hosts and supports, and methods for immobilization of indicator dyes. Further and more specific sections summarize the state of the art in materials with dual functionality (indicator and host), nanomaterials, sensors based on upconversion and 2-photon absorption, multiparameter sensors, imaging, and sensors for extreme pH values. A chapter on the many sensing formats has subsections on planar, fiber optic, evanescent wave, refractive index, surface plasmon resonance and holography based sensor designs, and on distributed sensing. Another section summarizes selected applications in areas, such as medicine, biology, oceanography, bioprocess monitoring, corrosion studies, on the use of pH sensors as transducers in biosensors and chemical sensors, and their integration into flow-injection analyzers, microfluidic devices, and lab-on-a-chip systems. An extra section is devoted to current challenges, with subsections on challenges of general nature and those of specific nature. A concluding section gives an outlook on potential future trends and perspectives.
Collapse
Affiliation(s)
- Andreas Steinegger
- Institute
of Analytical Chemistry and Food Chemistry, Graz University of Technology, Stremayrgasse 9, A-8010 Graz, Austria
| | - Otto S. Wolfbeis
- Institute
of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, D-93040 Regensburg, Germany
| | - Sergey M. Borisov
- Institute
of Analytical Chemistry and Food Chemistry, Graz University of Technology, Stremayrgasse 9, A-8010 Graz, Austria
| |
Collapse
|
10
|
Pastore A, Badocco D, Pastore P. Kinetic response of pH colorimetric sensors: Role of the cationic surfactant concentration and amount and type of solvent used in the preparation of the sensing spot. Microchem J 2020. [DOI: 10.1016/j.microc.2020.104891] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
11
|
Frankær CG, Sørensen TJ. Investigating the Time Response of an Optical pH Sensor Based on a Polysiloxane-Polyethylene Glycol Composite Material Impregnated with a pH-Responsive Triangulenium Dye. ACS OMEGA 2019; 4:8381-8389. [PMID: 31459927 PMCID: PMC6648965 DOI: 10.1021/acsomega.9b00795] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 04/30/2019] [Indexed: 05/07/2023]
Abstract
Determining the time it takes a sensor to report a change in the concentration of its target analyte may appear to be an easy task, but it is not. The dynamic characteristic of a sensor is determined by all components in the sensor system and the hydrodynamics of the sample. Here, the dynamic properties of an optical pH sensor were determined using the IUPAC-recommended activity step method in experimental setups that can determine sensor-limited response times longer than 5 s. In order to do so, experimental setups for the injection and for the dipping method of determining the sensor time response were developed, tested, and shown to be able to determine time-response curves with 1 s time resolution. This time resolution is shown to be sufficient for determining dynamic characterization of this optical pH sensor. The sensor chemistry-limited time-response curves were analyzed using curve fitting. It was found that the optode response time is limited by diffusion of protons within the sensor material when the proton concentration is reduced and limited by diffusion from the bulk to the boundary layer at the optode surface when proton concentration is increased. The latter is dependent on the magnitude of the change in analyte concentration and cannot be reported as a single response time. The investigation of the time response of the optical pH sensor reveals detailed information of the sensor chemistry, but does not yield a single response time of the sensor capable of describing the dynamic sensor characteristics of the optical pH sensor system.
Collapse
Affiliation(s)
- Christian G. Frankær
- Nano-Science
Center & Department of Chemistry, University
of Copenhagen, Universitetsparken
5, 2100 Copenhagen, Denmark
- E-mail: (C.G.F.)
| | - Thomas J. Sørensen
- Nano-Science
Center & Department of Chemistry, University
of Copenhagen, Universitetsparken
5, 2100 Copenhagen, Denmark
- FRS-systems
ApS, Hovedgaden 20, 4621 Gadstrup, Denmark
- E-mail: (T.J.S.)
| |
Collapse
|
12
|
Frankær CG, Sørensen TJ. A unified approach for investigating chemosensor properties - dynamic characteristics. Analyst 2019; 144:2208-2225. [PMID: 30839988 DOI: 10.1039/c9an00268e] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Chemosensors are a group of sensors-responsive sensor chemistry, sensor hardware, and software-that report on the composition of solutions and gaseous samples. Dynamic properties are fundamental for all sensor characterization. While electrochemical chemosensors have seen a century of research and are well-described, research on chemosensors using other modes of transductions are still at an early stage. The dynamic properties of chemosensors-independent of their mode of transduction-are not reported consistently in the literature. This makes it impossible to compare sensor performance of chemosensors from different manufacturers and laboratories. To remedy this, standardized experimental methods that exclude the influence of drift and any dependence on activity step change must be used. Subsequently, the resulting data must be treated using a unifying analysis formalism, and robust values must be used to describe chemosensor characteristics. Characterizing the sensor properties in turn enables rationalizing the link between sensor performance and sensor chemistry. Following a review of sensor theory, a thorough discussion of experimental methods and data analysis models for determining dynamic sensor properties, we arrive at evidence-based recommendations for good practice when describing new chemosensors. Adhering to these recommendations, sensor performance can be compared between laboratories, and information on the sensor chemistry may be revealed in the data analysis. This topic is particularly relevant in the rapidly maturing field of optical chemosensors.
Collapse
Affiliation(s)
- Christian G Frankær
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark.
| | | |
Collapse
|
13
|
Frankær CG, Rosenberg M, Santella M, Hussain KJ, Laursen BW, Sørensen TJ. Tuning the p K a of a pH Responsive Fluorophore and the Consequences for Calibration of Optical Sensors Based on a Single Fluorophore but Multiple Receptors. ACS Sens 2019; 4:764-773. [PMID: 30762336 DOI: 10.1021/acssensors.9b00148] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Since Sørensen and Bjerrum defined the pH scale, we have relied on two methods for determining pH, the colorimetric or the electrochemical. For pH electrodes, calibration is easy as a linear response is observed in the interesting pH range from 1 to ∼12. For colorimetric sensors, the response follows the sigmoidal Bjerrum diagram of an acid-base equilibrium. Thus, calibration of colorimetric sensors is more complex. Here, seven pH responsive fluorescent dyes based on the same diazaoxatriangulenium (DAOTA) fluorophore linked to varying receptor groups were prepared. Photoinduced electron transfer (PeT) quenching from appended aniline or phenol receptors generated the pH response of the DAOTA dyes, and the position of the p Ka value of the dye was tuned using the Hammett relationship as a guideline. The fluorescence intensity of the dyes in a sol-gel matrix environment was measured as a function of pH in universal buffer, and it was found that the dyes behave as perfect pH responsive probes under these conditions. The response of optical pH sensors is nonlinear and was found to be limited to 2-3 pH units for a precision of 0.01 pH unit. As sensors with a broader sensitivity range can be achieved by mixing multiple dyes with different p Ka values, mixtures of dyes in solution were investigated, and a broad range pH sensor with a precision of 0.006 pH units over a range of 3.6 pH units was demonstrated. Further, approximating the sensor response as linear was considered, and a limiting precision for this approach was determined. As the responses of the pH responsive DAOTA dyes were found to be ideally sigmoidal and as the six dyes were shown to have p Ka values scattered over a range from ∼2 to ∼9, this allows for design of a broad range optical pH sensor in the pH range from 1 to 10. This hypothesis was tested using quaternary mixtures of the different DAOTA dyes, and these were found to behave as a direct sum of the individual components. Thus, while linear calibration is limited to a precision of 0.02 in a range of 2-3 pH units, calibration using ideal sigmoidal functions is possible in the range of 1-10 with a precision better than 0.01, and as good as 0.002 pH units.
Collapse
Affiliation(s)
- Christian G. Frankær
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
- FRS-systems ApS, Hovedgaden 20, 4621 Gadstrup, Denmark
| | - Martin Rosenberg
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
| | - Marco Santella
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
| | | | - Bo W. Laursen
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
| | - Thomas J. Sørensen
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
- FRS-systems ApS, Hovedgaden 20, 4621 Gadstrup, Denmark
| |
Collapse
|
14
|
Rosenberg M, Junker AKR, Sørensen TJ, Laursen BW. Fluorescence pH Probes Based on Photoinduced Electron Transfer Quenching of Long Fluorescence Lifetime Triangulenium Dyes. CHEMPHOTOCHEM 2019. [DOI: 10.1002/cptc.201800266] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Martin Rosenberg
- Nano-Science Center and Department of ChemistryUniversity of Copenhagen Universitetsparken 5 DK-2100 Copenhagen Ø Denmark
| | - Anne Kathrine R. Junker
- Nano-Science Center and Department of ChemistryUniversity of Copenhagen Universitetsparken 5 DK-2100 Copenhagen Ø Denmark
| | - Thomas Just Sørensen
- Nano-Science Center and Department of ChemistryUniversity of Copenhagen Universitetsparken 5 DK-2100 Copenhagen Ø Denmark
| | - Bo W. Laursen
- Nano-Science Center and Department of ChemistryUniversity of Copenhagen Universitetsparken 5 DK-2100 Copenhagen Ø Denmark
| |
Collapse
|
15
|
Frankær CG, Hussain KJ, Dörge TC, Sørensen TJ. Optical Chemical Sensor Using Intensity Ratiometric Fluorescence Signals for Fast and Reliable pH Determination. ACS Sens 2019; 4:26-31. [PMID: 30592615 DOI: 10.1021/acssensors.8b01485] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Optical pH sensors enable noninvasive monitoring of pH, yet in pure sensing terms, the potentiometric method of measuring pH is still vastly superior. Here, we report a full spectrometer-based optical pH sensor system consisting of sensor chemistry, hardware, and software that for the first time is capable of challenging the performance of an electrode-based pH meter in specific applications such as biopharmaceutical process monitoring and in single-use bioproduction. A highly photostable triangulenium fluorophore emitting at 590 nm was immobilized in an organically modified silicon matrix that allows for fast time-response by rapid diffusion of water in and out of the resulting composite polymer deposited on a polycarbonate substrate. Fluctuations from the fiber optical sensor hardware have been reduced by including a highly photostable terrylene-based reference dye emitting at 660 nm, thus enabling intensity-based ratiometric readouts. The dyes were excited by 505 nm light from a light emitting diode. The sensor was operational within a pH range of 4.6-7.6, and was characterized and demonstrated to have properties that are comparable to those of commercial pH electrodes considering time-response ( t90 < 90 s), precision (0.03 pH-units), and drift.
Collapse
Affiliation(s)
- Christian G. Frankær
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
- FRS-systems ApS, Hovedgaden 20, 4621 Gadstrup, Denmark
| | | | - Tommy C. Dörge
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
| | - Thomas J. Sørensen
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
- FRS-systems ApS, Hovedgaden 20, 4621 Gadstrup, Denmark
| |
Collapse
|
16
|
Dalfen I, Dmitriev RI, Holst G, Klimant I, Borisov SM. Background-Free Fluorescence-Decay-Time Sensing and Imaging of pH with Highly Photostable Diazaoxotriangulenium Dyes. Anal Chem 2018; 91:808-816. [PMID: 30518209 DOI: 10.1021/acs.analchem.8b02534] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Novel fluorescent diazaoxatriangulenium (DAOTA) pH indicators for lifetime-based self-referenced pH sensing are reported. The DAOTA dyes were decorated with phenolic-receptor groups inducing fluorescence quenching via a photoinduced-electron-transfer mechanism. Electron-withdrawing chlorine substituents ensure response in the most relevant pH range (apparent p Ka' values of ∼5 and 7.5 for the p, p-dichlorophenol- and p-chlorophenol-substituted dyes, respectively). The dyes feature long fluorescence lifetimes (17-20 ns), high quantum yields (∼60%), and high photostabilities. Planar optodes are prepared upon immobilization of the dyes into polyurethane hydrogel D4. Apart from the response in the fluorescence intensity, the optodes show pH-dependent lifetime behavior, which makes them suitable for studying 2D pH distributions with the help of fluorescence-lifetime-imaging techniques. The lifetime response is particularly pronounced for the sensors with high dye concentrations (0.5-1 wt % with respect to the polymer) and is attributed to the efficient homo-FRET mechanism.
Collapse
Affiliation(s)
- Irene Dalfen
- Institute of Analytical Chemistry and Food Chemistry , Graz University of Technology , Stremayrgasse 9 , 8010 Graz , Austria
| | - Ruslan I Dmitriev
- School of Biochemistry and Cell Biology , University College Cork , T12 K8AF Cork , Ireland.,Institute for Regenerative Medicine , I.M. Sechenov First Moscow State University , 119146 Moscow , Russian Federation
| | | | - Ingo Klimant
- Institute of Analytical Chemistry and Food Chemistry , Graz University of Technology , Stremayrgasse 9 , 8010 Graz , Austria
| | - Sergey M Borisov
- Institute of Analytical Chemistry and Food Chemistry , Graz University of Technology , Stremayrgasse 9 , 8010 Graz , Austria
| |
Collapse
|
17
|
Idumah CI, Hassan A, Ihuoma DE. Recently emerging trends in polymer nanocomposites packaging materials. POLYM-PLAST TECH MAT 2018. [DOI: 10.1080/03602559.2018.1542718] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Christopher Igwe Idumah
- Enhanced Polymer Engineering Group, Faculty of Chemical Engineering, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia
| | - Azman Hassan
- Enhanced Polymer Engineering Group, Faculty of Chemical Engineering, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia
| | - David Esther Ihuoma
- Enhanced Polymer Engineering Group, Faculty of Chemical Engineering, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia
- Department of TVE, Food and Nutrition Unit, Ebonyi State University, Abakaliki, Nigeria
| |
Collapse
|
18
|
Shi XM, Mei LP, Zhang N, Zhao WW, Xu JJ, Chen HY. A Polymer Dots-Based Photoelectrochemical pH Sensor: Simplicity, High Sensitivity, and Broad-Range pH Measurement. Anal Chem 2018; 90:8300-8303. [DOI: 10.1021/acs.analchem.8b02291] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Xiao-Mei Shi
- State Key Laboratory of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Li-Ping Mei
- State Key Laboratory of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Nan Zhang
- State Key Laboratory of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Wei-Wei Zhao
- State Key Laboratory of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
| | - Jing-Juan Xu
- State Key Laboratory of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Hong-Yuan Chen
- State Key Laboratory of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
| |
Collapse
|