Engineered Nucleotide Chemicapacitive Microsensor Array Augmented with Physics-Guided Machine Learning for High-Throughput Screening of Cannabidiol.

The recent legalization of cannabidiol (CBD) to treat neurological conditions such as epilepsy has sparked rising interest across global pharmaceuticals and synthetic biology industries to engineer microbes for sustainable synthetic production of medicinal CBD. Since the process involves screening large amounts of samples, the main challenge is often associated with the conventional screening platform that is time consuming, and laborious with high operating costs. Here, a portable, high-throughput Aptamer-based BioSenSing System (ABS3 ) is introduced for label-free, low-cost, fully automated, and highly accurate CBD concentrations' classification in a complex biological environment. The ABS3 comprises an array of interdigitated microelectrode sensors, each functionalized with different engineered aptamers. To further empower the functionality of the ABS3 , unique electrochemical features from each sensor are synergized using physics-guided multidimensional analysis. The capabilities of this ABS3 are demonstrated by achieving excellent CBD concentrations' classification with a high prediction accuracy of 99.98% and a fast testing time of 22 µs per testing sample using the optimized random forest (RF) model. It is foreseen that this approach will be the key to the realistic transformation from fundamental research to system miniaturization for diagnostics of disease biomarkers and drug development in the field of chemical/bioanalytics.

Carbon Allotrope-Based Optical Fibers for Environmental and Biological Sensing: A Review.

Recently, carbon allotropes have received tremendous research interest and paved a new avenue for optical fiber sensing technology. Carbon allotropes exhibit unique sensing properties such as large surface to volume ratios, biocompatibility, and they can serve as molecule enrichers. Meanwhile, optical fibers possess a high degree of surface modification versatility that enables the incorporation of carbon allotropes as the functional coating for a wide range of detection tasks. Moreover, the combination of carbon allotropes and optical fibers also yields high sensitivity and specificity to monitor target molecules in the vicinity of the nanocoating surface. In this review, the development of carbon allotropes-based optical fiber sensors is studied. The first section provides an overview of four different types of carbon allotropes, including carbon nanotubes, carbon dots, graphene, and nanodiamonds. The second section discusses the synthesis approaches used to prepare these carbon allotropes, followed by some deposition techniques to functionalize the surface of the optical fiber, and the associated sensing mechanisms. Numerous applications that have benefitted from carbon allotrope-based optical fiber sensors such as temperature, strain, volatile organic compounds and biosensing applications are reviewed and summarized. Finally, a concluding section highlighting the technological deficiencies, challenges, and suggestions to overcome them is presented.

Functionalized Fiber End Superstructure Fiber Bragg Grating Refractive Index Sensor for Heavy Metal Ion Detection.

We present a novel superstructure fiber Bragg grating fiber end sensor capable of detecting variations in refractive index (RI) of liquids and potentially that of gases, and demonstrated an application in the detection of heavy metal ions in water. The sensor is capable of sensing RI variations in the range of 1.333 to 1.470 with good sensitivity of up to 230 dB/RIU achieved for the RI range of 1.370 to 1.390. The sensor is capable of simultaneously measuring variations in ambient temperature along with RI. A simple chemical coating was employed as a chelating agent for heavy metal ion detection at the fiber end to demonstrate an possible application of the sensor. The coated fiber sensor can conclusively detect the presence of heavy metal ions with concentrations upwards of 100 ppm. RI sensing capability of the sensor is neither affected by temperature nor strain and is both robust and easily reproducible.

Carbon Dot-functionalized Interferometric Optical Fiber Sensor for Detection of Ferric Ions in Biological Samples.

This work reports an interferometric optical microfiber sensor functionalized with nitrogen- and sulfur-codoped carbon dots (CDs) for the detection of ferric ions (Fe3+). Compared to other CD-based ferric ion sensors, the sensing mechanism of this presented sensor is dependent on the refractive index modulations due to selective Fe3+ adsorption onto the CD binding sites at the tapered region. This is the first study in which CD-based sensing was performed at the solid phase as a chelator, which does not rely on its fluorescence properties. The detection performance of the proposed sensor is not only comparable to a conventional fluorescence-based CD nanoprobe sensor but also capable of delivering quantitative analysis results and ease of translation to a sensor device for on-site detection. The presented sensor exhibits Fe3+ detection sensitivity of 0.0061 nm/(µg/L) in the linear detection range between 0 and 300 µg/L and a detection limit of 0.77 µg/L based on the Langmuir isotherm model. Finally, the potential use of the CD-functionalized optical microfiber sensor in the real environmental and biological Fe3+ monitoring applications has also been validated in this work.

Biogreen Synthesis of Carbon Dots for Biotechnology and Nanomedicine Applications.

Over the past decade, carbon dots have ignited a burst of interest in many different fields, including nanomedicine, solar energy, optoelectronics, energy storage, and sensing applications, owing to their excellent photoluminescence properties and the easiness to modify their optical properties through doping and functionalization. In this review, the synthesis, structural and optical properties, as well as photoluminescence mechanisms of carbon dots are first reviewed and summarized. Then, we describe a series of designs for carbon dot-based sensors and the different sensing mechanisms associated with them. Thereafter, we elaborate on recent research advances on carbon dot-based sensors for the selective and sensitive detection of a wide range of analytes, including heavy metals, cations, anions, biomolecules, biomarkers, nitroaromatic explosives, pollutants, vitamins, and drugs. Lastly, we provide a concluding perspective on the overall status, challenges, and future directions for the use of carbon dots in real-life sensing.

An Advanced Hand-Held Microfiber-Based Sensor for Ultrasensitive Lead Ion Detection.

This study demonstrated a l-glutathione-modified nonadiabatic microfiber sensor to detect a trace level of heavy metal ions in aqueous solution. The sensor showed an exclusively selective response to Pb2+ among other metal ions and a measured detection limit of 5 µg/L, lower than the maximum allowable limit of Pb2+ in drinking water by the World Health Organization. Moreover, a novel compact all-fiber-based interrogation scheme was proposed to promote the development of a portable hand-held system for on-site measurement. The presented scheme does not require costly and bulky laboratory equipment but operates based on the reflected optical power of two fiber Bragg gratings (FBG), measured using photodetectors independently.

Narratives in Two Languages: Storytelling of Bilingual Cantonese-English Preschoolers.

PURPOSE: The aim of this study was to compare narratives generated by 4-year-old and 5-year-old children who were bilingual in English and Cantonese. METHOD: The sample included 47 children (23 who were 4 years old and 24 who were 5 years old) living in Toronto, Ontario, Canada, who spoke both Cantonese and English. The participants spoke and heard predominantly Cantonese in the home. Participants generated a story in English and Cantonese by using a wordless picture book; language order was counterbalanced. Data were transcribed and coded for story grammar, morphosyntactic quality, mean length of utterance in words, and the number of different words. RESULTS: Repeated measures analysis of variance revealed higher story grammar scores in English than in Cantonese, but no other significant main effects of language were observed. Analyses also revealed that older children had higher story grammar, mean length of utterance in words, and morphosyntactic quality scores than younger children in both languages. Hierarchical regressions indicated that Cantonese story grammar predicted English story grammar and Cantonese microstructure predicted English microstructure. However, no correlation was observed between Cantonese and English morphosyntactic quality. CONCLUSIONS: The results of this study have implications for speech-language pathologists who collect narratives in Cantonese and English from bilingual preschoolers. The results suggest that there is a possible transfer in narrative abilities between the two languages.

Posterior colpotomy: a successful retrieval route for pelvic masses following robot-assisted laparoscopic surgery.

We report a technique of transvaginal extraction of pelvic masses or larger specimens removed during robot-assisted laparoscopic surgery in order to avoid larger port incisions and postoperatively reduce pain. Fifty women underwent a transvaginal incision to remove large pelvic masses after robot-assisted laparoscopic hysterectomies. Posterior colpotomies were performed with bagged specimens delivered into the vagina, extracted, and then closed robotically with a running suture. Vaginal extraction of pelvic masses was successful in all attempted cases and in no case was there any spillage, with an average operative time of 94.22 ± 4.48 and no intraoperative complications. This technique can be considered efficacious and safe with minimal morbidity. We suggest a surgical set-up including vaginal-cervical Ahluwalia retractor elevator to be prepared should the specimen be too large to remove via the port site, thus giving the surgeon the opportunity to perform this procedure with ease if necessary.