Nuclear magnetic resonance (NMR) spectroscopy is a widely used tool for chemical analysis and molecular structure identification. Because it typically relies on the weak magnetic fields produced by a small thermal nuclear spin polarization, NMR suffers from poor molecule-number sensitivity compared to other analytical techniques. Recently, a new class of NMR sensors based on opticallyprobed nitrogen-vacancy (NV) quantum defects in diamond have allowed molecular spectroscopy from sample volumes several orders of magnitude smaller than the most sensitive inductive detectors. To date, however, NV-NMR spectrometers have only been able to observe signals from pure, highly concentrated samples. To overcome this limitation, we introduce a technique that combines picoliter-scale NV-NMR with fully integrated Overhauser dynamic nuclear polarization (DNP) to perform high-resolution spectroscopy on a variety of small molecules in dilute solution, with femtomole sensitivity. Our technique advances mass-limited NMR spectroscopy for drug and natural product discovery, catalysis research, and single cell studies. Main text:Nuclear magnetic resonance (NMR) sensors based on nitrogen vacancy (NV) centers, point quantum defects in diamond, provide unprecedented detection of signals from small sample volumes 1-3 . While most early realizations of NV-detected NMR had limited spectral resolution (~1 kHz), recent work has shown that resolution 1 Hz, sufficient to observe chemical shifts and scalar couplings ('J-couplings'), can be achieved in micrometer-scale NV-NMR detectors by employing a synchronized readout technique 4-6 . This advance opens the possibility of applying NV-NMR to a variety of next-generation analytic technologies, such as single-cell analysis 7 and metabolomics 8,9 , and high-throughput screening of mass-limited chemical reactions [10][11][12] . However, because the relevant sample volumes are so small (picoliter-scale), NV-NMR spectroscopy has to date only been applicable to pure molecular samples 4,13 . This restriction precludes many potential chemical, biochemical, and biophysical applications, unless sensitivity improvements can be realized to enable the detection of dilute molecules in solution.Here, we demonstrate a new technique to address this challenge using high-resolution, micrometer-scale NV-NMR in combination with in-situ hyperpolarization of the sample nuclear spins, resulting in an improvement of more than two orders of magnitude in molecule-number

Sustainable human-computer interaction is investigating the role of persuasive and gamified technologies in encouraging people to engage in a more sustainable lifestyle. Motivation is a key requirement for behavior change, yet many persuasive systems do not sufficiently account for motivational aspects. In this paper we investigate under which circumstances components such as feedback and game elements (e.g., rewards) afford user motivation. The result is a taxonomy of design components that is grounded in well-established psychological theories on motivation. We illustrate how the taxonomy can contribute to the design of meaningful persuasive technologies by discussing a case study from the domain of sustainable mobility behavior (the project GoEco!).

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The present urban transportation system, mostly tailored for cars, has long shown its limitations. In many urban areas, public transportation and soft mobility would be able to effectively satisfy many travel needs. However, they tend to be neglected, due to a deep-rooted car dependency. How can we encourage people to make sustainable mobility choices, reducing car use and the related CO 2 emissions and energy consumption? Taking advantage of the wide availability of smartphone devices, we designed GoEco!, a smartphone application exploiting automatic mobility tracking, eco-feedback, social comparison and gamification elements to persuade individual modal change. We tested the effectiveness of GoEco! in two regions of Switzerland (Cantons Ticino and Zurich), in a large-scale, one year long randomized controlled trial. Notwithstanding a large drop-out rate experienced throughout the experiment, GoEco! was observed to produce a statistically significant impact (a decrease in CO 2 emissions and energy consumption per kilometer) for systematic routes in highly car-dependent urban areas, such as the Canton Ticino. In Zurich, instead, where high quality public transport is already available, no statistically significant effects were found. In this paper we present the GoEco! experiment and discuss its results and the lessons learnt, highlighting practical difficulties in performing randomized controlled trials in the field of mobility and providing recommendations for future research.

NMR is a noninvasive, molecular-level spectroscopic technique widely used for chemical characterization. However, it lacks the sensitivity to probe the small number of spins at surfaces and interfaces. Here, we use nitrogen vacancy (NV) centers in diamond as quantum sensors to optically detect NMR signals from chemically modified thin films. To demonstrate the method’s capabilities, aluminum oxide layers, common supports in catalysis and materials science, are prepared by atomic layer deposition and are subsequently functionalized by phosphonate chemistry to form self-assembled monolayers. The surface NV-NMR technique detects spatially resolved NMR signals from the monolayer, indicates chemical binding, and quantifies molecular coverage. In addition, it can monitor in real time the formation kinetics at the solid–liquid interface. With our approach, we show that NV quantum sensors are a surface-sensitive NMR tool with femtomole sensitivity for in situ analysis in catalysis, materials, and biological research.

Chronic pain is currently treated with opioids that offer unsatisfactory long-term analgesia and produce serious side effects. There is a clear need for alternative therapies. Herein, peptide-based hydrogels are used as extended-release drug delivery carriers. Two different formulations were developed: the drug is coformulated within the hydrogel; the drug is an integral part of the hydrogelator. Both strategies afford a prolonged and significant antinociception up to 72 h after subcutaneous administration in mice.

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