Reversible colorimetric sensing of volatile analytes by wicking in close proximity to a photonic film.

Isolation of volatile analytes from environmental or biological fluids is a rate-determining step that can delay the response time for continuous sensing. In this paper, we demonstrate a colorimetric sensing system that enables the rapid detection of gas-phase analytes released from a flowing micro-volume fluid sample. The sensor platform is an analyte-responsive metal-insulator-metal (MIM) thin-film structure integrated with a large area quartz micropillar array. This allows precise planar alignment and microscale separation (310 µm) of the optical and fluidic structures. This configuration offers rapid and homogeneous color changes over large areas that permits detection by low-resolution optics or eye, which is well-suited to portable/wearable devices. For our proof-of-principle demonstration, we utilized a poly(methyl methacrylate) (PMMA) spacer and evaluated the sensor's response (color change) to ethanol vapor. We show that the RGB color value is quantitatively linked to the spacer swelling, which is reversible and repeatable. The optofluidic platform reduces the sensor response time from minutes to seconds compared with experiments using a conventional chamber. The sensor's concentration-dependent response was examined, confirming the potential of the reported sensing platform for continuous, compact, and quantitative colorimetric analysis of volatile analytes in low-volume samples, such as biofluids.

Screening Electrocardiograms Have Low Utility in Medical Clearance Before Pediatric Inpatient Psychiatric Admission.

OBJECTIVES: Children presenting to the emergency department (ED) requiring psychiatric admission often undergo screening electrocardiograms (ECG) as part of the medical clearance process. The diagnostic yield of screening ECGs for this purpose has not been reported. The purpose of this study was to determine the clinical utility of screening ECGs in children and adolescents requiring acute inpatient psychiatric admission. METHODS: A single-center retrospective study of patients aged 5 to 18 years who did not have documented indications for ECG and underwent screening ECG before psychiatric inpatient admission over a 2-year period was conducted. Abnormal ECGs were identified via chart review and were reinterpreted by a pediatric cardiologist to determine potential significance to psychiatric care. Impact on treatment and disposition was examined. RESULTS: From January 2018 through December 2019, 252 eligible pediatric patients had a screening ECG in the ED before psychiatric admission. Twenty-one (8.3%) of these ECGs were interpreted as abnormal, and 6 (2.4%) were determined to be potentially relevant to psychiatric care in the setting of specific medication use. The abnormal ECG interpretations resulted in additional workup and/or cardiology consultation for 7 (2.7%) patients but had no impact on psychiatric admission. CONCLUSIONS: In the absence of concerning individual or family history or cardiac symptoms, routine screening ECGs as part of medical clearance for psychiatric admission are not warranted given the low yield of meaningful findings. The decision to obtain an ECG should be made with careful consideration of medical history and in the presence of specific indications.