Real-time, noise and drift resilient formaldehyde sensing at room temperature with aerogel filaments

Formaldehyde, a known human carcinogen, is a common indoor air pollutant. However, its real-time and selective recognition from interfering gases remains challenging, especially for low-power sensors suffering from noise and baseline drift. We report a fully 3D-printed quantum dot/graphene-based aerogel sensor for highly sensitive and real-time recognition of formaldehyde at room temperature. By optimising the morphology and doping of the printed structures, we achieve a record-high response of 15.23 percent for 1 parts-per-million formaldehyde and an ultralow detection limit of 8.02 parts-per-billion consuming only 130 uW power. Based on measured dynamic response snapshots, we also develop an intelligent computational algorithm for robust and accurate detection in real time despite simulated substantial noise and baseline drift, hitherto unachievable for room-temperature sensors. Our framework in combining materials engineering, structural design and computational algorithm to capture dynamic response offers unprecedented real-time identification capabilities of formaldehyde and other volatile organic compounds at room temperature.Comment: Main manuscript: 21 pages, 5 figure. Supplementary: 21 pages. 13 Figures, 2 tabl

Universal Murray's law for optimised fluid transport in synthetic structures

Materials following Murray's law are of significant interest due to their unique porous structure and optimal mass transfer ability. However, it is challenging to construct such biomimetic hierarchical channels with perfectly cylindrical pores in synthetic systems following the existing theory. Achieving superior mass transport capacity revealed by Murray's law in nanostructured materials has thus far remained out of reach. We propose a Universal Murray's law applicable to a wide range of hierarchical structures, shapes and generalised transfer processes. We experimentally demonstrate optimal flow of various fluids in hierarchically planar and tubular graphene aerogel structures to validate the proposed law. By adjusting the macroscopic pores in such aerogel-based gas sensors, we also show a significantly improved sensor response dynamic. Our work provides a solid framework for designing synthetic Murray materials with arbitrarily shaped channels for superior mass transfer capabilities, with future implications in catalysis, sensing and energy applications.Comment: 19 pages, 4 figure

Highly Sensitive And Selective Electrochemical Dopamine Sensing Properties Of Multilayer Graphene Nanobelts

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)In the present study, we report the electrochemical sensing property of multi-layer graphene nanobelts (GNBs) towards dopamine (DA). GNBs are synthesized from natural graphite and characterized by using techniques like field-emission scanning electron microscopy, atomic force microscopy and Raman spectroscopy. An electrochemical sensor based on GNBs is developed for the detection of DA. From the cyclic voltammetry and amperometry studies, it is found that GNBs possess excellent electrocatalytic activity towards DA molecules. The developed DA sensor showed a sensitivity value of 0.95 mu A mu M-1 cm(-2) with a linear range of 2 mu M to 0.2 mM. The interference data exhibited that GNB is highly selective to DA even in the presence of common interfering species like ascorbic acid, uric acid, glucose and lactic acid.277University Grant commissionIndia-UK-India Education and Research Initiative (UGC-UKIERI) [UGC-2013-14/005]CNPq (Brazil)DST-CNPq/India-Brazil bilateral Cooperation [INT/Brazil/P-12/2013]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Electrochemical Sensing Of Hydrazine Using Multilayer Graphene Nanobelts

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The electrochemical sensing property of multi-layer graphene nano-belts (GNB) towards hydrazine is studied. The developed hydrazine sensor showed a sensitivity value of 0.08 mu A mu M-1 cm(-2) with a linear range of 10 mu M to 1.36 mM. The interference data also exhibited high selectivity to hydrazine even in the presence of common interfering species like ascorbic acid, uric acid, glucose and lactic acid.6141132911334University Grant commission, India-UK-India Education and Research Initiative (UGC-UKIERI) [UGC-2013-14/005]CNPq (Brazil)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Electrochemical Sensing Of Bisphenol Using A Multilayer Graphene Nanobelt Modified Photolithography Patterned Platinum Electrode

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)An electrochemical sensor has been developed for the detection of Bisphenol-A (BPA) using photolithographically patterned platinum electrodes modified with multilayer graphene nanobelts (GNB). Compared to bare electrodes, the GNB modified electrode exhibited enhanced BPA oxidation current, due to the high effective surface area and high adsorption capacity of the GNB. The sensor showed a linear response over the concentration range from 0.5 mu M-9 mu M with a very low limit of detection. = 37.33 nM. In addition, the sensor showed very good stability and reproducibility with good specificity, demonstrating that GNB is potentially a new material for the development of a practical BPA electrochemical sensor with application in both industrial and plastic industries.2737University Grant commission, India-UK-India Education and Research Initiative (UGC-UKIERI) [UGC-2013-14/005]CNPq (Brazil)DST-CNPq/India-Brazil bilateral Cooperation [INT/Brazil/P-12/2013]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Electrochemical 4-chlorophenol sensing properties of plasma-treated multilayer graphene modified photolithography patterned platinum electrode

The present work describes the electrochemical 4-chlorophenol (4-CP) sensing properties of multilayer graphene samples (MLG). In order to enhance the presence of oxygen functional groups and to increase the edge plane defects, oxygen plasma treatment is adopted. Raman, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM) characterizations are used to investigate the effect of plasma treatment on MLG. Compared to pristine MLG, the oxygen plasma treated one shows increased oxidation current towards 4-CP. The sensor data exhibit high sensitivity and stability with high anti-interference property in the presence of other phenolic compounds including phenol, bisphenol, 2,3-chlorophenol, 2,3,4-nitrophenol and inorganic ions

Electrochemical sensing of bisphenol using a multilayer graphene nanobelt modified photolithography patterned platinum electrode

An electrochemical sensor has been developed for the detection of Bisphenol-A (BPA) using photolithographically patterned platinum electrodes modified with multilayer graphene nanobelts (GNB). Compared to bare electrodes, the GNB modified electrode exhibited enhanced BPA oxidation current, due to the high effective surface area and high adsorption capacity of the GNB. The sensor showed a linear response over the concentration range from 0.5 μM–9 μM with a very low limit of detection = 37.33 nM. In addition, the sensor showed very good stability and reproducibility with good specificity, demonstrating that GNB is potentially a new material for the development of a practical BPA electrochemical sensor with application in both industrial and plastic industries

Electrochemical sensing of bisphenol using a multilayer graphene nanobelt modified photolithography patterned platinum electrode

An electrochemical sensor has been developed for the detection of Bisphenol-A (BPA) using photolithographically patterned platinum electrodes modified with multilayer graphene nanobelts (GNB). Compared to bare electrodes, the GNB modified electrode exhibited enhanced BPA oxidation current, due to the high effective surface area and high adsorption capacity of the GNB. The sensor showed a linear response over the concentration range from 0.5 µM – 9 µM with a very low limit of detection = 37.33 nM. In addition, the sensor showed very good stability and reproducibility with good specificity, demonstrating that GNB is potentially a new material for the development of a practical BPA electrochemical sensor with application in both industrial and plastic industries