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We report graphyne nanosheet as a carrier for drugs, namely quercetin and 5-fluorouracil to the target cell for the treatment of hepatocellular carcinoma and colorectal carcinoma, which causes major cancer-related death. In the proposed study, ab initio calculations were performed for the investigation of adsorption energy, bandgap, average bandgap changes, and Bader charge transfer; upon physisorption of the quercetin and 5-fluorouracil on graphyne nanosheets. Furthermore, the chemical hardness, electrophilicity, and chemical potential are also explored upon interaction of quercetin and 5-fluorouracil on graphyne sheets. The significant parameters give the insights on the interaction of the quercetin and 5-fluorouracil drugs onto the graphyne, and the preferential interaction sites of these drugs in graphyne are investigated. The findings of the present research work recommend that the graphyne nanosheet can be effectively utilized as a quercetin and 5-fluorouracil drug delivery vehicle.

The adsorption of cyanogen fluoride and chloride gas molecules on red phosphorene (RP) nanosheet was investigated using the first-principles calculation. We confirmed the geometric solidity of RP nanosheet using the formation energy and the energy band gap is detected to be 0.72 eV. The most stable adsorption configurations of cyanogen halides are studied by energy band gap variation, Bader charge transfer, and adsorption energy. We observed the physisorption type of interaction upon exposure of cyanogen halides on RP nanosheet. Furthermore, the band gap structure along with the density of states spectrum indicates the physisorption of cyanogen halide on RP nanosheet. The variation in the band gap upon adsorption leads to modify the resistance of RP nanosheet. The findings show that RP nanosheets can be used to detect the presence of cyanogen chloride and fluoride.

We report the interaction of stanane nanosheet (Sn-NS) with deoxy ribo nucleic acids (DNA)/ribo nucleic acids (RNA) utilizing density functional theory (DFT) technique. The calculated formation energy led us to conclude that Sn-NS exhibits a stable geometric structure. The energy band structure and density of states (DOS) spectrum provide the electronic characteristics of Sn-NS, and the band gap is found to be 1.73 eV, which exhibit semiconducting property. Our results confirmed the adsorption of nucleobases with stanane nanosheet, which follows the sequence C > U > A > T > G. The interaction property of nucleobases on Sn-NS material is authenticated with the Bader charge transfer, energy gap, adsorption energy and average energy gap changes. Moreover, the interaction of nucleobases on Sn-NS is also explored using the change in the DOS-spectrum, electron density diagrams and energy band structure. The findings of the current work infer that the DNA sequencing can be carried out using stanane nanosheet.

We explore the electronic properties of germanene nanotubes (GeNTs) using first-principles calculations with the non-equilibrium Green’s function technique. The adsorption of two different gases, namely NO2 and SO2, onto GeNT is investigated using van der Waals density functional technique. Moreover, the change in the band gap-energy is noticed upon interaction of small NO2 and SO2 gas molecules. The shift in the peaks is observed in the conduction band upon adsorption of small NO2 and SO2 molecules on the GeNT. The calculated adsorption energies range from − 0.156 to − 0.609 eV. The transmission spectrum showed that the transition of electrons is prominent for SO2 molecules rather than NO2 molecules onto the GeNT. In addition, the electron density diagram also indicate that a transfer of electrons occurs among the gas molecules and the GeNT electroresistive molecular device. The I–V characteristics of GeNT device clearly reveal the change in the current, which varies in the magnitude from 10−9 to 10−6 A upon adsorption of gas molecules on GeNT device. Thus, we suggest that germanene nanotube molecular device can be employed for the detection of NO2 and SO2 small molecules.

We studied the geometric stability of pristine graphyne nanosheet (Gpn-NS) and electronic properties for the possible use of graphyne sheet for the chemical sensor. The center of attention of the work is to probe the nitroaromatic compounds (NACs) at the earlier stage of chemical explosion using Gpn-nanosheet material. The geometric stability of pristine Gpn base material is entrenched with the formation energy and also verified with phonon band structure. The interaction of different NACs such as hexanitrostilbene, M-dinitrobenzene, picric acid, and 2,4,6-trinitrotoluene on Gpn material is studied in connection with the Bader charge transfer, average energy gap changes, adsorption energy, and band gap. Moreover, the adsorption energy of NACs on Gpn-NS varies in the order of − 0.178 to − 0.627 eV. The outcomes of the suggested work infer that Gpn-NS can be used to probe the NAC vapors.

In the present work, using generalized gradient approximation (GGA) in accordance with the Perdew-Burke-Ernzerhof (PBE) functional we studied the adsorption of three harmful gas molecules namely ammonia (NH3), nitrogen dioxide (NO2) and phosphine (PH3) on the surface of the bismuthene nanotube (BiNT). We studied the response of BiNT as a chemi-resistor sensor for NH3, NO2 and PH3 gas molecules with regards to three essential features, namely energy gap variation, Bader charge transfer as well as the adsorption energy. Our results demonstrate that BiNT can indeed be successfully used as a chemical nanosensor for detection of NH3, NO2, and PH3 molecules.

We ascertained the structural firmness of β-antimonene nanotube and studied the adsorption behaviour of sulfadimethoxine (SM) and tetracycline (TC) molecules on the base substrate using density functional theory (DFT) with B86LYP-D3 level of theory. Significantly, β-antimonene nanotube displays a semiconducting character with an energy band-gap of 0.263 eV. The three dissimilar preferential adsorption sites namely, bride-, hollow-, tube-inner site of SM and TC molecules on β-antimonene nanotube were investigated using average band gap changes, Bader charge transfer along with adsorption energy. Further, the calculated adsorption energy for preferential adsorption sites is noticed to be in the scope of −0.813 eV to −3.752 eV signifying to physisorption and chemisorption form of interaction on β-antimonene nanotube. The inclusive outcome recommends that β-antimonene nanotube can be deployed as a chemi-resistive sensor to sense and remove SM and TC molecules from the contaminated aqueous medium.

The success of graphene and other two-dimensional layered materials opens the way for potential applications. In this report, we investigated the structural stability of twisted bilayer beta phosphorene (TB-PNS) and found stable from the formation energy. Besides, TB-PNS falls in the semiconductor classification with an energy band gap of 0.663 eV. The TB-PNS is deployed as a base substrate to adsorb formaldehyde and methanol vapours. Moreover, the chemi-resistive nature of TB-PNS is observed owing to the adsorption and desorption of formaldehyde and methanol molecules. Also, the electronic properties such as band structure, density of states, and electron density difference show a significant variation due to the adsorption of formaldehyde and methanol. Hence, the results suggest that TB-PNS is a suitable sensing base substrate for formaldehyde and methanol.

In recent days, researchers are focussing on 2D and 1D materials after the emergence of graphene and carbon nanotubes. The emergence of graphene and its analogue nanomaterials with fascinating properties encouraged the researchers to advent for different mono-element based two-dimensional nanomaterials (2-D NMs). One such element to appeal the scientific community is the arsenic (As) – group VA element. In this review, we provide state-of-the-art with regard to synthesis and various applications of group-VA arsenene nanostructures. Firstly, we discussed the prediction of different structures of arsenene. Secondly, the general properties of arsenene nanostructures are portrayed. The various methods in the synthesis of arsenene are presented along with the applications of arsenene in various fields. Also, the electronic properties of arsenene nanoribbon, nanotube, and nanosheets are studied and presented. The current review will give the insights on properties, synthesis, and applications of various arsenene nanostructures. Finally, the current review throws light on the prospects and various applications of arsenene nanostructures.

The potent removal of the chlorinated persistent organic pollutants (POPs) that are categorized as “Dirty Dozen” by the Stockholm Convention – Aldrin and Dieldrin, by (8,8) armchair blue-Phosphorene nanotube (blue-PNT) is explored in the study by utilising the density functional framework. Besides, the structural firmness of the chief component is affirmed from the negative magnitude of cohesive formation energy (−3.766 eV per atom). Further, the significant interaction features of the POPs interacted blue-PNT like the supreme adsorption energy, average band gap variation, and desirable Bader charge transfer proposes the utility of blue-PNT to remove the POPs – aldrin and dieldrin.

The electronic attributes and energetics of e-arsenene nanosheet (e-As) are explored with regard to the density functional theory basis. Initially, based on formation energy (−3.715 eV/atom), we ensured the structural firmness of e-As. The e-As is used as a base substrate to adsorb nucleobases viz., adenine (A), guanine (G), thymine (T), cytosine (C) & uracil (U). The surface adsorption of nucleobases on e-As is analysed based on band structure, the density of states, adsorption energy, energy gap variation & charge transfer. Besides, we observed the exothermic nature of binding energy (ranging from −0.453 eV to −0.819 eV) upon nucleobase adsorption on e-As. Also, the energy gap variation & charge transfer takes place owing to adsorption of nucleobases on the e-As sheet. The present report reveals the adsorption of nucleobases on e-arsenene nanosheet.

The deamination and decarboxylation of the Amino Acid – Asparagine results in Volatile Fatty Acid (VFA) – Lactate and Polyamine – Putrescine, which are culpable for the release of malicious odors into the atmosphere. In the present research, the bio-molecules (Asparagine, Lactate and Putrescine) are taken as primary molecules and are admitted to interact with the two-dimensional nanomaterial – Kagome form of Phosphorene nanotube (Kagome-PNT) by wielding the density functional theory mode. The conformational stability of the Kagome-PNT is affirmed with the help of formation energy and crystal orbital Hamiltonian population (COHP) analysis. Besides, the electronic features of the pure Kagome-PNT and bio-molecules interacted Kagome-PNT (complex) are estimated in addition to the COHP analysis on the complexes at the spot of bio-molecule interaction (hollow and triangle-spot). Further, the interaction features namely the binding energy, average energy gap alteration and Bader charge transfer are gauged so that our recommendation of wielding Kagome-PNT as a fundamental component in chemi-resistive based detector to sense the existence of bio-molecules (asparagine, lactate and putrescine) can be confirmed.

In this research, two-dimensional material, black-phosphorene nanosheets (Black-PNS) have been deployed as a sensing substrate for detecting two tear gas molecules, namely, benzyl bromide and bromo...

Dimethyl ether (DME) and ethyl methyl ether (EME) are highly toxic volatile organic compounds (VOCs) that find their potential importance in many industries. Besides, DME and EME are highly flammable VOCs, which may cause a fire hazard. Also, both DME and EME are toxic to humans and animals. Thus, the detection of ether molecules in the atmosphere is important using chemical sensors. The novel β-antimonene nanosheet (β-SbNS) is taken as a base substrate to study the interaction behaviour of DME and EME molecules on the surface using density functional theory (DFT) method. Moreover, β-SbNS possesses semiconductor nature with an energy gap of 1.293 eV. At first, the structural stability of β-SbNS was confirmed with the negative magnitude of cohesive formation energy. In addition, the electronic characteristics of β-SbNS are studied in terms of the projected-density of states and band maps. Importantly, different global minima sites (bridge, ring, and top) of DME and EME vapour on β-SbNS were explored with the influence of significant factors, namely adsorption energy, average band gap changes, and Bader charge transfer. The findings of the proposed work advocate that β-SbNS can be competently used as a chemi-resistive sensor to detect DME and EME vapour molecules.

The electronic and adsorption properties of dimethyl and methyl-ethyl ester molecules on a silicene nanoring (SiNR) are studied using first-principles calculations. The adsorption properties of dimethyl and methyl-ethyl ester molecules on the surface of a silicene nanoring is investigated in terms of density of states spectrum, adsorption energy, average energy gap variation, Mulliken charge and Bader charge transfer. The structural stability of the SiNR is ensured using formation energy. The variation in the electron density and energy gap is noticed upon adsorption of dimethyl and methyl-ethyl ester molecules in the SiNR base material compared with its isolated counterpart. The highlights of the present work are silicene nanoring is used as a base material for ester molecule adsorption. The adsorption behavior of ester molecules is studied using energy band structure. The DOS spectrum confirms the transfer of electrons between the SiNR and ester molecules. The findings suggest that a SiNR can be used as a base material for the detection of dimethyl and methyl-ethyl ester molecules.

We present the chemisorption of chlortetracycline (CTC) and oxytetracycline (OTC) on theta phosphorene nanoribbon (theta-PNRibbon) based on the first-principles framework. The formation energy of theta-PNRibbon is noticed to be −3.759 eV per atom, which ensures structural stability. The theta-PNRibbon exhibits a band gap of 1.376 eV that belongs to the semiconductor. The presence of CTC and OTC molecules on a water medium requires a removal substrate. The adsorption energy for the complex structure is found to be in the range of −2.778 eV to −9.268 eV. Based on the adsorption energy and charge transfer between CTC and OTC molecules and theta-PNRibbon, the chemisorption of target molecules is observed. Also, the electronic properties of theta-PNRibbon owing to adsorption of CTC and OTC molecules are investigated with band structure and density of states studies. The findings reveal that theta-PNRibbon is one of the base substrates for the removal of CTC and OTC in the water bodies.

We report on the basis of density functional theory, the field emission properties of pristine and doped aluminum nanocone (Al-NC). We substituted the apex of the Al-NC with group IV and group V elements, namely arsenic (As), germanium (Ge) and phosphorous (P) atoms and had carried out studies on these nanocone structures. The density of states (DOS) spectrum gives a clear perception of the charge distribution over the Al-NC surface on doping. Furthermore, the Richardson-Dushman formula has been used to correlate the work function Φ and the charge density. We have observed that doping at the apex of Al-NC leads to the variation in work function Φ. The results show that the field emission properties of Al-NC can be improved with the substitution of As, Ge, and P at the apex of the structure. Our findings suggest that doping of the Al-NC with Ge, As and P leads to the improved field emission properties, which can be used for nanoelectronics and vacuum electronics.

The geometric stability of silicane layer (H-Si) is explored using the first-principles investigation. The electronic properties of H-Si are ascertained, and tunable electronic properties of H-Si leads to the application in sequencing the deoxyribonucleic acid (DNA)/riboxy nucleic acid (RNA). The adsorption behavior of DNA/RNA nucleobases on H-Si is explored using Bader charge transfer, adsorption energy, and energy gap. Moreover, there is a significant change in the band structure and density of states of H-Si upon adsorption of nucleobases. We observed that all the nucleobases are physisorbed on H-Si via van der Waals interaction. The adsorption of nucleobases on H-Si is in the order G > C > A = T > U. The findings of the result demonstrate that H-Si can be used to identify the nucleobases, which can be used for DNA/RNA sequencing in medical science and biotechnology.

The capability of graphdiyne nanotube is valued as drug delivery system in the delivery of commercially known drugs namely, Imuran (Azathioprine), which aids in the cure of Crohn's disease and rheumatoid arthritis, Pentasa (Mesalazine) used to treat Crohn's and other inflammatory diseases, Hyoscyamine (Daturine) is used to control few of the Parkinson's disease symptoms. In the present work, density functional theory calculations are carried out and explored the most deciding parameter namely, Bader charge transfer, adsorption energy, band gap and average energy gap variation upon adsorption of the drugs on graphdiyne. Furthermore, the chemical potential, chemical hardness and electrophilicity of graphdiyne nanotube are also reported. The parameters mentioned above give a clear perception on the adsorption of the drugs on to the graphdiyne nanotube, and the most protuberant adsorption sites of drugs on graphdiyne nanotube are studied. Besides, it is recognized that the drug Pentasa is known to be adsorbed more followed by the drug Hyoscyamine and Imuran. The outcome of the proposed work suggested that the graphdiyne nanotube can be effectively utilized as a drug delivery system for the chronic disease drugs.

The recent advances in the molecular device fabrication have outstretched the exciting applications in vapor sensing devices. This report investigates the explosive vapor detection using the antimonene molecular device (AMD) implemented with the first-principles study. The adsorption of four different explosive vapors namely hexanitrostilbene, M-dinitrobenzene, picric acid, and 2,4,6-trinitrotoluene on AMD device is examined. The adsorption configurations, charge transfer, band gap variation of antimonene nanosheet upon adsorption of explosive vapors on AMD are studied. The adsorption of vapors on AMD device is supported with the transmission spectrum and current-voltage features. Further, the results suggest that next-generation nanosensor is conceivable using antimonene nanosheets.

The explosive vapors like 2,4-dinitrotoluene, M-dinitrobenzene, 2,4,6-trinitrophenol, and 2,4,6-trinitrotoluene are detected with the aid of arsenene nanotube (As-NT). In order to identify the adsorption capability of explosive vapors on arsenene nanotube, its electronic properties are explored. The transmission of electrons between the As-NT and the explosive vapors are affirmed from the density of states spectrum and charge transfer. Moreover, the adsorption energy, energy band gap and Bader charge transfer of the isolated and explosive vapors adsorbed on As-NT validate the adsorption behavior. The findings suggest that the trace level of explosive vapors can be sensed using chemi-resistive based As-NT nanosensor.

Using first-principles calculation, the electronic properties including geometrical stability of bare (BSi) and hydrogenated silicene (HSi) and hydrogen vacant silicane sheets (HvSi) are investigated. The geometrical stability of BSi, HSi and HvSi nanosheets are ensured in accordance with the formation energy and phonon band structure. The prime emphasis of the proposed work is to detect the exhaled human breath biomarkers and to detect the earlier stage of lung cancer disease using HvSi base material. Moreover, the adsorption of various breath biomarkers namely, 2,3,4-trimethyl hexane, 4-methyl octane, ethyl benzene and undecane molecules on HvSi material is explored with essential parameters namely Bader charge transfer, energy gap, adsorption energy and average energy gap variation. Moreover, the interaction of biomarkers with HvSi base material changes the adsorption energy of the base material, which is noticed to be in the range of −0.778 to −1.274 eV. The novel feature of the present study is to detect the lung cancer disease at the earlier stage upon adsorption of breath biomarkers on HvSi nanosheets.

Density functional theory (DFT) simulations have been performed to study the field emission characteristics of pristine, Ga, and Al substituted germanium nanocone (Ge-NC). The influence due to the substitution of group-III elements on Ge-NC is studied using the density of states (DOS) spectrum and electron density. As a matter of fact, from the molecular electrostatic potential surface, it is noticed that the impurity substitution at the apex of Ge-NC leads to increase in the field emission properties due to delocalization of electron by the charge transfer at the apex of nanocone. In addition, the Mulliken charge transfer, work function and current density of the emitted electron were calculated for the pristine and Ga and Al-doped Ge-NC. The results suggest that the substitution of group-III impurity along the apex of Ge-NC leads to the improved field emission, which can be used for the assembly of vacuum electronics and nanoelectronics.

We report the electronic properties of black phosphorene nanoring (BPN) and adsorption behavior of chronic kidney disease biomarker vapors on BPN. The designed BPN is stable, which is ensured by the formation energy with a value of −3.857eV/atom. The band gap of BPN is recorded as 0.716eV showing the semiconductor property. The prominent kidney disease biomarker vapors, namely isoprene, pentanal, hexanal, heptanal are allowed to interact on BPN and studied based on adsorption property on BPN. Based on charge transfer, energy band gap variation and adsorption energy, we studied the adsorption behavior of BPN towards kidney disease biomarkers. Our findings show that BPN can be used to detect the presence of kidney biomarkers.

The electronic properties of borophene nanotube (BNT) are witnessed and the adsorption properties of dimethyl amine (DMA) and trimethyl amine (TMA) molecules on borophene nanotube are explored through non-equilibrium Green’s function (NEGF) and density functional theory (DFT) method. The device density of states spectrum interprets the change in peak maxima, thus indicating the electron transition between DMA, TMA molecules and BNT base material. I-V characteristics strengthen the adsorption property of DMA and TMA on BNT by pointing out the variation in the current. The present work assures that borophene nanotube (BNT) can be employed as DMA and TMA sensor.

Using ab initio calculation, structural stability, including electronic properties of bare/hydrogenated stanene (BSn/HSn) nanosheet, was explored. The geometrical stability of HSn material is verified with the influence of phonon band structure and formation energy. The concentration of the present work is to check the quality of Musa acuminata (banana) fruits when it is in ripe and overripe stage using HSn nanosheet material. Further, the interaction of different volatile organic compounds, namely, isoamyl acetate, isobutyl acetate, acetoin, and 2,3-butanediol aromas on HSn base material is studied with the significant parameter such as Bader charge transfer, band gap, adsorption energy, and average energy band gap changes. The sensitivity of the aromas emitting from ripe and overripe stages of banana on HSn nanosheet was studied using density of states spectrum. The adsorption energy of HSn nanosheet is found in the range of − 0.055 to − 0.989 eV upon the interaction VOCs of Musa acuminata. The novel aspect of the present work is to check the quality of Musa acuminata with the influence of HSn nanosheet using density functional theory.

Using ab initio technique, electronic properties including structural stability of the chair-like graphane nanosheet (HGr-NS) and nanotube (HGr-NT) is explored. The structural stability of graphane nanosheet/nanotube is confirmed with the influence of formation energy and phonon band structure. The density-of-states spectrum provides the insights on charge transfer upon these small molecules adsorbed on graphane material. The energy band gap of graphane base material get differs when toxic gas molecules (NO2 and SO2) interacted with HGr-NS and HGr-NT. The adsorption energy upon interaction of NO2 and SO2 molecules on graphane material is found to be in the range of −0.5 and −0.3 eV, respectively. Further, the average energy gap variation of graphane system is noticed to be in the range of 34.67 to 55.95% for NO2 adsorbed graphane and 87.3 to 151.45% for SO2 adsorption on graphane sheets. Notably, a shorter recovery time is obtained on graphane sensor upon desorption of SO2 molecules. Besides, the interaction of SO2 small molecule on hydrogenated graphene nanosheet and nanotube is found to be more favorable rather than NO2 molecules. The findings propose the application of HGr-NS and HGr-NT for the detection of NO2 and SO2 small molecules.

The geometric structure, electronic and adsorption properties of methanol, ethanol and 1-propanol molecules on hydrogenated graphene (graphane) were investigated using first-principles calculations. The stability of graphane base material is confirmed using formation energy and phonon band structures. The adsorption of alcohol molecules on bare graphane and hydrogen vacant graphane nanosheet is found to be prominent and the selectivity of alcohol molecules can be achieved using bare or hydrogen vacant graphane nanosheet. Moreover, the interaction of alcohol molecules on bare and hydrogen vacant graphane nanosheets is studied using the adsorption energy, energy band gap variation, Bader charge transfer and average energy band gap variation. The adsorption energy ranges from -0.149 to −0.383 eV upon alcohol adsorption. The energy gap varies from 4.71 to 2.62 eV for bare graphane and from 4.02 to 3.60 eV for hydrogen vacant graphane nanosheets upon adsorption of alcohol molecules. The adsorption properties of alcohol molecules provide useful information for the possible application of graphane nanosheet as a base material for the detection of alcohol molecules.

We report the adsorption properties of methanol (ML) and ethanol (EL) vapor molecules on to the monolayer MoSe2 surface. Before, studying the adsorption behavior, the structural stability of MoSe2 monolayer is ensured with formation energy. The stable monolayer MoSe2 nanosheet is used as a base material for the adsorption of ML and EL vapor molecules. The interaction of ML and EL vapors on MoSe2 surface layer is explored using the adsorption energy, energy gap variation and Bader charge analysis. We noticed the band gap variation between 1.43 and 1.88 eV upon adsorption of methanol and ethanol vapors on to MoSe2 nanosheets. Also the adsorption energy is found in the range of −0.375 to −0.732 eV upon the interaction of alcohol molecules on MoSe2 flakes. Besides, the density of states (DOS) spectrum and electron density clearly envisions the adsorption properties of ML and EL vapors on to the MoSe2 monolayers. Furthermore, a short recovery time is noticed for MoSe2 nanosheet material upon desorption of methanol and ethanol molecules. Moreover, the variation in the resistance of MoSe2 base material is noticed upon adsorption of ML and EL molecules. The findings show that monolayer MoSe2 nanosheets can be used as a chemi-resistance to detect the presence of ML and EL vapors in the environment.

The electronic properties and geometric stability of germanane nanosheet is explored using first-principle studies. The germanane nanosheet exhibits semiconducting properties and stability of germanane sheet is ensured with formation energy. The adsorption behavior of deoxyribo nucleic acid (DNA)/ribo nucleic acid (RNA) nucleobases on monolayer germanane nanosheet have been investigated using density functional theory with van der Waals dispersion correction. The adsorption of nucleobases is found to be physisorbed on germanane nanosheet with the van der Waals type of interaction. The order of adsorption of nucleobases with germanane nanosheet is known to be C > G > A > T > U. We observed the changes in the energy band structure and the density of states variation due to the adsorption of nucleobases on germanane nanosheet. Our results confirm that apart from graphene, germanane monolayer can be used to detect nucleotides in the field of biotechnology and medical science.

The adsorption behavior of ethanol vapor molecules on MnFe2O4 (MFO) nanostructures was carried out using first-principles calculation. The structural stability including electronic properties of MFO spinel structure is explored using ab-initio method. From the phonon energy band structure, it is observed that there are no imaginary frequencies, which confirms the geometric stability of MFO. The global minima interaction sites of ethanol on MFO nanostructure are studied. The adsorption of ethanol molecule is exothermic, and the adsorption energy is calculated to be − 0.448 to − 0.882 eV per molecule. The density of states spectrum and band structure of MFO nanostructure get modified when the sensing material is exposed to the ethanol molecule atmosphere. Moreover, the interaction behavior of ethanol vapor molecules on MFO molecular structure is investigated with reference to the adsorption energy, Bader charge analysis, percentage of average energy gap variation. The desorption of ethanol vapor from MFO material have been studied and low recovery time in the order of 0.025 s is noticed. In addition, the most suitable adsorption sites of ethanol vapor molecules on spinel MnFe2O4 is identified and reported. The findings suggest the application of MFO material for the sensing of ethanol molecules.

The electronic properties of monolayer aluminene nanosheet and adsorption properties of CO and NO gas molecules on aluminene nanosheet are investigated using first-principles studies for the first time. The density of states spectrum gives a clear picture regarding the transfer of charge upon adsorption of CO and NO gas molecules on aluminene nanosheet. The adsorption properties of CO and NO molecules on aluminene base material are explored in terms of average energy gap variation, natural bond orbital, HOMO-LUMO gap and adsorption energy. The most prominent adsorption sites of CO and NO molecules on aluminene are studied at an atomistic level. The state-of-the-art of aluminene base material gives the information regarding the development of chemical nanosensor. The findings of the present work suggest the use of monolayer aluminene nanosheet for the detection of CO and NO gas molecules.

The electronic properties of antimonene nanotubes and nanoribbons hydrogenated along the zigzag and armchair borders are investigated with the help of density functional theory (DFT) method. The structural stability of antimonene nanostructures is confirmed with the formation energy. The electronic properties of hydrogenated zigzag and armchair antimonene nanostructures are studied in terms of highest occupied molecular orbital (HOMO) & lowest unoccupied molecular orbital (LUMO) gap and density of states (DOS) spectrum. Moreover, due to the influence of buckled orientation, hydrogen passivation and width of antimonene nanostructures, the HOMO-LUMO gap widens in the range of 0.15–0.41 eV. The findings of the present study confirm that the electronic properties of antimonene nanostructures can be tailored with the influence of width, orientation of the edges, passivation with hydrogen and morphology of antimonene nanostructures (nanoribbons, nanotubes), which can be used as chemical sensor and for spintronic devices.

Using density functional theory method, we investigate the adsorption properties of NH3 and NO2 molecules on stanene and stanane nanosheets. The adsorption of molecules is explored based on the charge transfer, energetics, energy band gap and average energy gap variation. Moreover, the optimal adsorption sites of NH3 and NO2 molecules are identified on stanene and stanane nanosheets. Besides, the state-of-the-art provides the key features for the development of chemi-resistive nanosensor based on stanene and stanane nanosheets upon adsorption of NH3 and NO2 molecules. Furthermore, the study shows that adsorption of NO2 molecules is more prominent rather than NH3 molecules.

The stanene nanotube is designed and used for the detection of trimethyl amine (TMA) and n-butyl amine (n-BA) vapors, which is investigated using first-principles study. The electronic properties of bare stanene nanotube and the adsorption properties of TMA and n-BA molecules are studied using density functional theory with non-equilibrium Green’s function. Moreover, the device density of states shows the shift in the peak maxima upon adsorption of TMA and n-BA molecules on to the stanene nanotube. The variation in the flow of electron is noticed upon adsorption of TMA and n-BA molecules in the transmission spectrum of stanene nanotube. I-V characteristics clearly confirm the variation in the current upon adsorption of TMA and n-BA molecules. The findings of the study clearly suggest that the stanene nanotube molecular device can be used for the detection of trace levels of TMA and n-BA molecules present in the atmosphere.

The structural stability and electronic properties of zigzag graphdiyne nanosheet is studied using density functional theory (DFT) technique. The adsorption behavior of dimethyl amine (DMA) and trimethyl amine (TMA) vapor molecules on graphdiyne nanosheet are also investigated with DFT method. The density-of-states (DOS) spectrum gives the perception on charge transfer upon adsorption of DMA/TMA on graphdiyne nanosheet. The energy band gap changes upon the interaction of DMA/TMA vapors on graphdiyne nanosheet. The adsorption of DMA/TMA is studied in terms of Bader charge analysis, band gap, adsorption energy and average energy gap variation. A short recovery time is noticed on graphdiyne sensor upon desorption of DMA/TMA molecules. The most prominent adsorption sites of DMA/TMA on graphdiyne nanosheet are identified at an atomistic level. The interaction of DMA on graphdiyne nanosheet is observed to be more prominent rather than TMA vapor molecules. The findings of the present work clearly support the application of graphdiyne nanosheet for the detection of DMA/TMA vapor molecules.

The electronic properties of Oligo-p-phenylene molecular device are studied through density functional theory (DFT) in combination with non-equilibrium Green's function (NEGF). The electronic transport properties of Oligo-p-phenylene molecular device are investigated in terms of I-V characteristics, transmission spectrum and total density of states (TDOS). The TDOS gets modified with the number of phenyl units present in the device and also the applied bias voltage influence Oligo-p-phenylene molecular device. The density of charge along Oligo-p-phenylene molecular device is observed in both the conduction band and in the valence band upon increasing bias voltage. The transmission spectrum of Oligo-p-phenylene molecular device provides the insights on the transition of electrons across various energy intervals. The results of the present work clearly show that Oligo-p-phenylene molecular device can be utilized as negative differential resistance (NDR) device and its NDR property can be fine-tuned with the bias voltage and also by the number of phenyl units.

The density functional theory (DFT) method with non-equilibrium Green’s function (NEGF) method is used to study the electronic properties of the graphyne nanotube device. The graphyne nanotube is used as a base material to graft photochromic spiropyran and merocyanine molecules. The current voltage characteristics clearly give the insights on the switching properties of spiropyran and merocyanine grafted graphyne device. The findings show that spiropyran grafted graphyne device as ON state and merocyanine grafted graphyne device as an OFF state device. Moreover, upon shining light of proper wavelength, the spiropyran/merocyanine grafted graphyne nanotube device can be used as a switch.

The electronic properties of zigzag graphdiyne nanosheet and nanotube are investigated using first-principles studies. The adsorption behavior of ammonia molecules on graphdiyne nanosheet are studied using density functional theory. The density-of-states spectrum gives insights on transfer of charge upon interaction of NH3 gas molecules on graphdiyne nanostructures. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) gap vary upon interaction with ammonia gas molecules on graphdiyne nanostructure. The adsorption properties of NH3 molecules on graphdiyne nanostructures are studied in terms of natural bond orbital, HOMO-LUMO gap, adsorption energy and average energy gap variation. The structural stability of graphdiyne base material is confirmed with the help of formation energy. A shorter recovery time is observed in graphdiyne sensor material during adsorption and desorption process of ammonia molecules. The most favorable adsorption sites of NH3 on graphdiyne are investigated in an atomistic level. The interaction of NH3 on graphdiyne nanosheet is observed to be more prominent rather than graphdiyne nanotube. The findings of the present study support the use of zigzag graphdiyne nanosheets for the detection of ammonia molecules.

The functionalization of boron nitride (B12N12/B16N16) nanoclusters with glycine in gaseous and aqueous environments were studied. The corresponding changes of spectroscopic, electronic, and thermodynamic properties of the B12N12 and B16N16 nanoclusters were evaluated by means of the density functional theory (DFT) calculations. Analysis of the binding energies shows that the interaction of glycine amino acid toward B12N12 is more remarkable than B16N16 in the gas and solvent environments. Thermodynamic properties also indicate that the glycine molecule energetically prefers to interact with the B12N12 and B16N16 nanoclusters through its amine group rather than carbonyl and hydroxyl groups. Our calculations also demonstrated that the electronic features of B12N12 and B16N16 nanoclusters on the adsorption of glycine from its carbonyl group in the aqueous environment is more altered than the amine and hydroxyl groups. Molecular docking shows that the [(NH2)-Glycine]2/B12N12 complex has a good binding affinity with protein tumor necrosis factor-alpha (TNF-α) and interleukin-1β (IL-1β) in comparison with the other glycine-BN nanocluster complexes thus making this hybrid bio-inorganic medium a promising material for biomedical and drug-delivery applications.

The density functional theory framework is used to study geometry and electronic properties of pristine tricycle arsenene nanoribbon (T-AsNR) and Ga substituted T-AsNR. The stable geometry of both T-AsNR is ensured based on the formation energies. The obtained formation energies for T-AsNR and Ga-substituted T-AsNR are −4.462 and −4.512 eV/atom, respectively. Also, the band gap is calculated to be 0.635 and 0.212 eV, respectively for pristine and Ga substituted T-AsNR, which are semiconductors. Furthermore, T-AsNR is used as a base substrate to adsorb sulfisoxazole in the aqueous medium. Moreover, the adsorption of sulfisoxazole on both T-AsNR possesses chemisorption. Besides, the adsorption energy at the valley site of T-AsNR and Ga-substituted T-AsNR are −6.313 eV and −6.346 eV. The average energy gap variation for Ga-substituted T-AsNR was highest at the top site and is about 174.06%, whereas the pristine one showed 6.93 %. The change in the electronic properties of T-AsNR is observed with regard to band structure, electron density, and density of states spectrum. Thus, the outcome suggests that T-AsNR is a prominent adsorbing medium of sulfisoxazole in contaminated water.

2D (two-dimensional) materials are emerging in today's world. Among the 2D materials, arsenene sheets are prominently used as chemical and biosensors. In the present work, the twisted bilayer arsenene sheets (TB-AsNS) are used to adsorb toluene and M-xylene vapours. Moreover, the band gap of pristine TB-AsNS is calculated to be 0.437 eV. Besides, the surface adsorption of toluene and M-xylene vapours modify the electronic properties of TB-AsNS noticed from the band structure, density of states, and electron density difference diagrams. The surface assimilation of target toluene and M-xylene on TB-AsNS falls in the physisorption regime facilitating the adsorption and desorption of molecules. Also, the charge transfer analysis infers that TB-AsNS acts as acceptor and target molecules play as donors. The findings support that TB-AsNS can be used as a sensing medium towards M-xylene and toluene.

Double and single-walled square-octagon allotrope of phosphorus nanotube (s-o PNT) is chosen as primary materials in the study to sense the presence of toxic styrene. The geometric stability of the two primary materials is ensured from the negative cohesive energy. The energy gap observed for the two primary materials are found to increase upon the adsorption of styrene at three distinct sites. Moreover, physisorption type of interaction is witnessed between the target pollutant and primary material, and a valid charge transmission between them is observed using Bader charge transfer and electron difference density. The observation of ample energy gap variation affirms the efficacy of utilising double-walled s-o PNT in sensing styrene hydrocarbon.

Recently the synthesis of two-dimensional (2D) phosphorene creates a research interest among researchers. Based on the density functional theory (DFT) framework, the energetics and electronic attributes of black phosphorene sheets (B-Ph) are explored. The stable B-Ph is deployed as a base substrate to adsorb liver cancer biomarker volatiles, such as 1-Octen-3-ol, hexanal, decane. The adsorption energy falls in the physisorption range owing to liver cancer biomarker volatiles adsorption on B-Ph. Besides, the energy band gap of 0.889 eV gets deviated upon the surface adsorption of liver cancer biomarkers. Also, the charge transfer and electron density difference support the deviation in the electronic properties of B-Ph owing to the assimilation of liver cancer volatiles. Hence, the results reveal that B-Ph is one of the prominent candidates to identify the presence of liver cancer volatiles from the exhaled breath.