@article{kudenov_krafft_scarboro_doherty_balint-kurti_2023, title={Hybrid spatial-temporal Mueller matrix imaging spectropolarimeter for high throughput plant phenotyping}, volume={62}, ISSN={["2155-3165"]}, DOI={10.1364/AO.483870}, abstractNote={Many correlations exist between
					spectral reflectance or transmission with various phenotypic responses
					from plants. Of interest to us are metabolic characteristics, namely,
					how the various polarimetric components of plants may correlate to
					underlying environmental, metabolic, and genotypic differences among
					different varieties within a given species, as conducted during large
					field experimental trials. In this paper, we overview a portable
					Mueller matrix imaging spectropolarimeter, optimized for field use, by
					combining a temporal and spatial modulation scheme. Key aspects of the
					design include minimizing the measurement time while maximizing the
					signal-to-noise ratio by mitigating systematic error. This was
					achieved while maintaining an imaging capability across multiple
					measurement wavelengths, spanning the blue to near-infrared spectral
					region (405–730 nm). To this end, we present our optimization
					procedure, simulations, and calibration methods. Validation results,
					which were taken in redundant and non-redundant measurement
					configurations, indicated that the polarimeter provides average
					absolute errors of (5.3±2.2)×10−3 and (7.1±3.1)×10−3, respectively. Finally, we provide
					preliminary field data (depolarization, retardance, and diattenuation)
					to establish baselines of barren and non-barren Zea maize hybrids (G90 variety), as captured from various
					leaf and canopy positions during our summer 2022 field experiments.
					Results indicate that subtle variations in retardance and
					diattenuation versus leaf canopy position may be present before they
					are clearly visible in the spectral transmission.}, number={8}, journal={APPLIED OPTICS}, author={Kudenov, Michael W. and Krafft, Danny and Scarboro, Clifton G. and Doherty, Colleen J. and Balint-Kurti, Peter}, year={2023}, month={Mar}, pages={2078–2091} }
 @article{hetzler_wang_krafft_jamalzadegan_overton_kudenov_ligler_wei_2022, title={Flexible sensor patch for continuous carbon dioxide monitoring}, volume={10}, ISSN={["2296-2646"]}, DOI={10.3389/fchem.2022.983523}, abstractNote={Monitoring and measurement of carbon dioxide (CO2) is critical for many fields. The gold standard CO2 sensor, the Severinghaus electrode, has remained unchanged for decades. In recent years, many other CO2 sensor formats, such as detection based upon pH-sensitive dyes, have been demonstrated, opening the door for relatively simple optical detection schemes. However, a majority of these optochemical sensors require complex sensor preparation steps and are difficult to control and repeatably execute. Here, we report a facile CO2 sensor generation method that suffers from none of the typical fabrication issues. The method described here utilizes polydimethylsiloxane (PDMS) as the flexible sensor matrix and 1-hydroxypyrene-3,6,8-trisulfonate (HPTS), a pH-sensitive dye, as the sensing material. HPTS, a base (NaOH), and glycerol are loaded as dense droplets into a thin PDMS layer which is subsequently cured around the droplet. The fabrication process does not require prior knowledge in chemistry or device fabrication and can be completed as quickly as PDMS cures (∼2 h). We demonstrate the application of this thin-patch sensor for in-line CO2 quantification in cell culture media. To this end, we optimized the sensing composition and quantified CO2 in the range of 0–20 kPa. A standard curve was generated with high fidelity (R2 = 0.998) along with an analytical resolution of 0.5 kPa (3.7 mm Hg). Additionally, the sensor is fully autoclavable for applications requiring sterility and has a long working lifetime. This flexible, simple-to-manufacture sensor has a myriad of potential applications and represents a new, straightforward means for optical carbon dioxide measurement.}, journal={FRONTIERS IN CHEMISTRY}, author={Hetzler, Zach and Wang, Yan and Krafft, Danny and Jamalzadegan, Sina and Overton, Laurie and Kudenov, Michael W. and Ligler, Frances S. and Wei, Qingshan}, year={2022}, month={Sep} }
 @article{kudenov_krafft_scarboro_doherty_balint-kurti_2021, title={Fieldable Mueller matrix imaging spectropolarimeter using a hybrid spatial and temporal modulation scheme}, volume={11833}, ISSN={["1996-756X"]}, DOI={10.1117/12.2593970}, abstractNote={Many correlations exist between spectral reflectance and various phenotypic responses from plants. Of interest to us are structural characteristics; namely, how the various spectral and polarimetric components may correlate to underlying environmental, metabolic, and genotypic differences among plant varieties within a given species. In this paper, we overview a portable Mueller matrix imaging spectropolarimeter that has been optimized for field use. Key aspects to the design included minimizing the measurement time while maximizing signal-to-noise ratio with low systematic errors. These goals must be achieved while maintaining an imaging capability across multiple measurement wavelengths, spanning the blue to near-infrared spectral region. To this end, we will review our optimization procedure, simulations, and experimental results, including preliminary field data taken from our summer 2021 field trials.}, journal={POLARIZATION SCIENCE AND REMOTE SENSING X}, author={Kudenov, Michael W. and Krafft, Danny and Scarboro, Clifton G. and Doherty, Colleen J. and Balint-Kurti, Peter}, year={2021} }