The misuse of cannabinoids and their synthetic variants poses significant threats to public health, necessitating the development of advanced techniques for detection of these compounds in biological or environmental samples. Existing methods face challenges like lengthy sample pretreatment and laborious antifouling steps. Herein, we present a novel sensing platform using magnetic nanorods coated with zwitterionic polymers for the simple, rapid, and sensitive detection of cannabinoids in biofluids. Our technique utilizes the engineered derivatives of the plant hormone receptor Pyrabactin Resistance 1 (PYR1) as drug recognition elements and employs the chemical-induced dimerization (CID) mechanism for signal development. Additionally, the magnetic nanorods facilitate efficient target capture and reduce the assay duration. Moreover, the zwitterionic polymer coating exhibits excellent antifouling capability, preserving excellent sensor performance in complex biofluids. Our sensors detect cannabinoids in undiluted biofluids like serum, saliva, and urine with a low limit of detection (0.002 pM in saliva and few pM in urine and serum) and dynamic ranges spanning up to 9 orders of magnitude. Moreover, the PYR1 derivatives demonstrate high specificity even in the presence of multiple interfering compounds. This work opens new opportunities for sensor development, showcasing the excellent performance of antifouling magnetic nanorods that can be compatible with different recognition units, including receptors and antibodies, for detecting a variety of targets.

Challenges associated with ADHD affect children's daily routines and response to environmental stimuli, and support from parents is helpful in managing and overcoming behavior regulation challenges. Positive reinforcement is increasingly integrated into family technologies for teaching regulation skills, but typically support specific co-located activities. To better understand how technology can support co-regulation within families with ADHD children, we deployed CoolTaco, a smartwatch and phone system to support collaboration in creating tasks, gaining points for achieving them, and redeeming rewards. Ten families with ADHD children used CoolTaco in their daily routines. By qualitatively analyzing family interviews and usage logs, we find that smartwatches can help provide pervasive regulation support to children, but the division across devices and parent-child roles interfere with developing independence. We discuss how technology should support co-regulation while also fostering future self-regulation, such as by guiding children in goal setting and helping them reflect on progress and achievements.

Distance learning in response to the COVID-19 pandemic presented tremendous challenges for many families. Parents were expected to support children's learning, often while also working from home. Students with Attention Deficit Hyperactivity Disorder (ADHD) are at particularly high risk for setbacks due to difficulties with organization and increased risk of not participating in scheduled online learning. This paper explores how smartwatch technology, including timing notifications, can support children with ADHD during distance learning due to COVID-19. We implemented a 6-week pilot study of a Digital Health Intervention (DHI) with ten families. The DHI included a smartwatch and a smartphone. Google calendars were synchronized across devices to guide children through daily schedules. After the sixth week, we conducted parent interviews to understand the use of smartwatches and the impact on children's functioning, and we collected physiological data directly from the smartwatch. Our results demonstrated that children successfully adopted the use of the smartwatch, and parents believed the intervention was helpful, especially in supporting the development of organizational skills in their children. Overall, we illustrate how even simple DHIs, such as using smartwatches to promote daily organization and task completion, have the potential to support children and families, particularly during periods of distance learning. We include practical suggestions to help professionals teach children with ADHD to use smartwatches to improve organization and task completion, especially as it applies to supporting remote instruction.

Plants sense abscisic acid (ABA) using chemical-induced dimerization (CID) modules, including the receptor PYR1 and HAB1, a phosphatase inhibited by ligand-activated PYR1. This system is unique because of the relative ease with which ligand recognition can be reprogrammed. To expand the PYR1 system, we designed an orthogonal * module, which harbors a dimer interface salt bridge; X-ray crystallographic, biochemical and in vivo analyses confirm its orthogonality. We used this module to create PYR1*MANDI/HAB1* and PYR1*AZIN/HAB1*, which possess nanomolar sensitivities to their activating ligands mandipropamid and azinphos-ethyl. Experiments in Arabidopsis thaliana and Saccharomyces cerevisiae demonstrate the sensitive detection of banned organophosphate contaminants using living biosensors and the construction of multi-input/output genetic circuits. Our new modules enable ligand-programmable multi-channel CID systems for plant and eukaryotic synthetic biology that can empower new plant-based and microbe-based sensing modalities.

A general method to generate biosensors for user-defined molecules could provide detection tools for a wide range of biological applications. Here, we describe an approach for the rapid engineering of biosensors using PYR1 (Pyrabactin Resistance 1), a plant abscisic acid (ABA) receptor with a malleable ligand-binding pocket and a requirement for ligand-induced heterodimerization, which facilitates the construction of sense-response functions. We applied this platform to evolve 21 sensors with nanomolar to micromolar sensitivities for a range of small molecules, including structurally diverse natural and synthetic cannabinoids and several organophosphates. X-ray crystallography analysis revealed the mechanistic basis for new ligand recognition by an evolved cannabinoid receptor. We demonstrate that PYR1-derived receptors are readily ported to various ligand-responsive outputs, including enzyme-linked immunosorbent assay (ELISA)-like assays, luminescence by protein-fragment complementation and transcriptional circuits, all with picomolar to nanomolar sensitivity. PYR1 provides a scaffold for rapidly evolving new biosensors for diverse sense-response applications.