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The development of power generators that can function in harsh snowy environments and in contact with snow can be beneficial but challenging to accomplish. Herein, we introduce the first snow-based triboelectric nanogenerator (snow-TENG) that can be used as an energy harvester and a multifunctional sensor based on the principle of snow-triboelectrification. In this work, we used a 3D printing technique for the precise design and deposition of the electrode and triboelectric layer, leading to flexible, stretchable and metal-free triboelectric generators. Based on the single electrode mode, the device can generate an instantaneous output power density as high as 0.2 mW/m(2), an open circuit voltage up to 8 V, and a current density of 40 μA/m(2). In addition, the snow-TENG can function as a miniaturized weather station to monitor the weather in real time to provide accurate information about the snowfall rate, snow accumulation depth, wind direction, and speed in snowy and/or icy environments. In addition, the snow-TENG can be used as a wearable power source and biomechanical sensor to detect human body motions, which may prove useful for snow-related sports. Unlike conventional sensor platforms, our design works without the need for batteries or image processing systems. We envision these devices could potentially be integrated into solar panels to ensure continuous power supply during snowy weather conditions.

There is an increased interest in using high-resolution mass spectrometry (HRMS) in the full scan mode (FS) for simultaneous qualitative and quantitative analysis with accurate mass based extracted ion chromatograms (HRMS-AM) for metabolomic profiling workflows. Herein, the capabilities and features of ‘MQ’, a common platform developed to support quantitative analysis from HRMS data are described. Module for qualitative annotation utilizes peak features that include mass accuracy, peak width, and relative abundance of isotopic distribution that offer reliable metabolic confirmation. Additionally, MQ provides multivariate clustering with Principal Component Analysis and a module for high-throughput database query based on user configurable annotated metabolite lists. MQ is capable of handling system-agnostic data formats from both direct HRMS and LC-HRMS analysis. Data processed using MQ for LC-HRMS-AM quantitation of amino acids benchmarked using a commercial tool is presented that validates the quantitative capabilities of the algorithm developed. Datasets representative of three different HRMS-AM based analysis scenarios have been showcased to demonstrate the utility of MQ.Availability and implementationFreely available on web at, http://www.ldims.com/services/software. MQ is implemented in Java and supported on Linux and Microsoft Windows system having Java runtime environment (JRE) pre-installed.

We report a low-cost, sensitive, bead-based electrochemical immunoarray for soluble L-selectin (or CD62L protein), a potential biomarker for staging bladder cancer. We used a semi-automated modular microfluidic array with online antigen capture on superparamagnetic beads, which were subsequently delivered to a detection chamber housing multiple sensors. The assay was designed to accurately detect CD62L in diluted serum with a limit of detection (LOD) of 0.25 ng mL(−1) and a dynamic range of 0.25–100 ng mL(−1). The microfluidic array gave significantly better accuracy and higher sensitivity than a standard ELISA kit, which was shown to be subject to significant systematic error at high and low concentration ranges. 31 serum samples from patients with varying grades of bladder cancer and cancer-free controls were analyzed by the immunoarray and ELISA, and the CD62L levels correlated. This work establishes a new accurate assay for determining CD62L levels and highlights the potential of this protein as a biomarker for detecting locoregional progression of bladder cancer.

Smart skin-like electronics are urgently crucial for artificial muscles, while the development of self-powered two-dimensional-like multifunctional material systems remains significant challenges. Here, we demonstrate a new class of printed smart electronic skin (SES) with multi-sensing properties and energy conversion capability using simple and cost-effective printing techniques. The resulting all-organic self-powering SES functioning as a human-monitoring device where it can detect a variety of external stimuli and works as an ultra-flexible biomechanical energy harvester. Remarkably, our SES exhibits excellent antibacterial properties in addition to self-adaptive performance under various conditions, such as being bent, cut, sewed, hammered, punctured, and washed. The proposed SES devices here have the promise for broad applications in future functional-wearables for human-machine interface, soft robotics, and skin prosthetics.

In addition to disease diagnostics, there is a need for biomarkers to predict severity of cancer therapy side effects such as oral mucositis. Oral mucositis is an inflammatory lesion of oral mucosa caused by high-dose chemotherapy and/or radiation that is especially prevalent during oral cancer treatment. We describe here a semi-automated, modular microfluidic immunoarray optimized for ultrasensitive detection of pro-inflammatory cytokines involved in pathobiology of oral mucositis. Our goal is to methodologically identify risk of mucositis early in oral cancer treatment, before the onset of lesions. Biomarkers include tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), interleukin-1 beta (IL-1 beta), and C-reactive protein (CRP). Protein analytes were captured from serum in a capture chamber by 1-mu m magnetic beads coated with antibodies and enzyme labels. Beads are then transported downstream to a detection chamber containing an eight-sensor array coated with glutathione-coated gold nanoparticles (GSH-AuNP) and a second set of antibodies to capture the beads with analyte proteins. In this first application of the immunoarray to four-protein multiplexed measurements, ultralow detection limits of 10-40 fg mL(-1) in 5 mu L serum were achieved for simultaneous detection in 30 min. Mass detection limits were 2.5-10 zmol, as few as 1500 molecules. Accuracy and diagnostic utility of the arrays were demonstrated by correlation of levels of the four biomarker proteins in serum from head and neck cancer patients with results from standard ELISA. This approach may lead to rapid, low-cost estimates of projected risk for severity of oral mucositis in cancer patients to enable improved therapeutic management.

A chromatography-free atmospheric pressure matrix-assisted laser desorption/ionization high-resolution massspectrometry (AP-MALDI HRMS) method is described for the simultaneous and quantitative detection of triazines and triazoles in grapes. The analytes were detected reproducibly with high mass accuracy (mass error within 5 ppm) and further confirmed by collision-induced dissociation fragmentation in tandem MS. The LODs and LOQs forall the analytes were found to be in the nanogram per gram level (15–20 ng/g LOQ). Internal standard–normalized high-resolution accurate mass–extracted (HR-AM) peak intensities of the detected ions were used to generate the concentration response curves. Linearity (with R2 values around 0.99) was obtained for these curves within a concentration range of 20–200 ng/g of the individual analytes. The accuracy and precision of the method were further established using QC samples. Validation and performancecomparison of the AP-MALDI HRMS method with an existing standard method using LC with triple quadrupole MS was carried out (evaluating sensitivity, accuracy, precision, and analysis time) using 20 table-grape field samples after QuEChERS extraction.

Isomeric asymmetric and symmetric dimethyl arginine (ADMA and SDMA respectively) residues are excreted in urine and are putative markers of cardiovascular and chronic kidney diseases. In this work, we demonstrate simultaneous and quantitative detection of endogeneous ADMA and SDMA from urine samples of healthy subjects using MALDI-TOF MS without any chromatographic separation. The DMA isomers yielded [M + H]+ ions along with their product ions formed due to MALDI in-source fragmentation. The precursor ions were validated using MALDI-TOF MS/MS as well as direct injection ESI-Q-TOF MS/MS. ADMA and SDMA generated unique product ions at ∼ m/z 46 and ∼ m/z 172 respectively in the MS-mode itself. These were advantageously used for full scan-mode absolute quantification of the isomeric metabolites. The m/z observed for all the ions was within 10 ppm mass accuracy. The calibration method was established by generating internal standard normalized peak area-based concentration response curves using synthetic standards. Good linearities (R2 > 0.95) with acceptable intra-assay, inter-assay variation (within 15% RSD) and excellent recoveries were observed for quality control samples. Finally, endogeneous concentrations of the metabolites were determined in urine from healthy subjects (n = 11). ADMA and SDMA were found to be in the range of 1.6–8 μM and 2.9–9.1 μM in urine and were in agreement with previously reported physiological levels.

Early detection of bladder cancer is crucial for improved patient outcomes, as patients see a sharp decline in 5-year survival rate from 80% to < 35%, at early or late stage diagnosis of the disease respectively. Gene expression studies indicated L-selectin (CD62L) as a potential protein biomarker indicative of metastatic bladder cancer. Here, a quantitative bead-based microfluidic immunoarray for CD62L expression in human serum is described. Sandwich immunoassay is established by surface binding of primary antibody on an 8-electrode carbon array and magnetic beads decorated with multiple detection antibodies and horseradish peroxidase enzyme-labels. Electrochemical detection is conducted by injecting a hydroquinone/hydrogen peroxide activator/mediator mixture for amperometric signal detection. Our analysis of 40 patient samples shows an overall increase in CD62L concentration with progression of disease stage. A drop-off in soluble CD62L is seen for late stage, high-grade metastatic tumors. In-depth statistical analysis is conducted to examine the comparative performance of traditional immunoassay and our modified immunoarray for CD62L.