Monolayer Of Molecules Research Articles

Double-side 2D/3D heterojunctions for inverted perovskite solar cells.

Defects at the top and bottom interfaces of three-dimensional (3D) perovskite photoabsorbers diminish the performance and operational stability of perovskite solar cells owing to charge recombination, ion migration and electric-field inhomogeneities1-5. Here we demonstrate that long alkyl amine ligands can generate near-phase-pure 2D perovskites at the top and bottom 3D perovskite interfaces and effectively resolve these issues. At the rear-contact side, we find that the alkyl amine ligand strengthens the interactions with the substrate through acid-base reactions with the phosphonic acid group from the organic hole-transporting self-assembled monolayer molecule, thus regulating the 2D perovskite formation. With this, inverted perovskite solar cells with double-side 2D/3D heterojunctions achieved a power conversion efficiency of 25.6% (certified 25.0%), retaining 95% of their initial power conversion efficiency after 1,000 h of 1-sun illumination at 85 °C in air.

Molecular Junctions for Terahertz Switches and Detectors.

Molecular electronics targets tiny devices exploiting the electronic properties of the molecular orbitals, which can be tailored and controlled by the chemical structure and configuration of the molecules. Many functional devices have been experimentally demonstrated; however, these devices were operated in the low-frequency domain (mainly dc to MHz). This represents a serious limitation for electronic applications, although molecular devices working in the THz regime have been theoretically predicted. Here, we experimentally demonstrate molecular THz switches at room temperature. The devices consist of self-assembled monolayers of molecules bearing two conjugated moieties coupled through a nonconjugated linker. These devices exhibit clear negative differential conductance behaviors (peaks in the current-voltage curves), as confirmed by ab initio simulations, which were reversibly suppressed under illumination with a 30 THz wave. We analyze how the THz switching behavior depends on the THz wave properties (power and frequency), and we benchmark that these molecular devices would outperform actual THz detectors.

Investigation of novel two-dimensional B2CO monolayer and its high sensing performance in detecting nitrogen-containing gases: A combined density functional theory calculation and non-equilibrium Green's function study

Two-dimensional (2D) materials have attracted widespread attention because of their excellent optical and electrical properties and have been extensively studied as gas sensors. A new type of 2D material, the B2CO monolayer, has recently been reported to possess significant structural, energetic, and thermodynamic stability. In this study, density functional theory (DFT) was used to explore the sensing properties of CO, CO2, NH3, NO, and NO2 gas molecules on the B2CO monolayer. After adsorption, the NH3, NO, and NO2 molecules formed chemical bonds with the B2CO monolayer. Among these, the NO2 molecule has the highest muscular adsorption energy in the B2CO monolayer. Based on electronic analysis, the B2CO monolayer can provide robust electron interactions with NO and NO2 molecules. Furthermore, the simulated current–voltage curves showed that the increasing amplitude of the current response for the adsorption of the NO2 molecule is more significant than that for NO. Thus, the calculated sensitivity for the NO2 molecules was much higher than that for the NO molecules in the B2CO monolayer. Based on these results, we predict that the B2CO monolayer will have a much higher sensing performance for detecting nitrogen-containing gases (NCGs) molecules than CO and CO2 molecules, especially NO2 molecules.

Electronic and Magnetic Properties of a Monolayer of VOTPP Molecules Sublimated on Ag(100)

AbstractVanadyl(IV) 5,10,15,20‐tetraphenylporphyrin (VOTPP) is an S = 1/2 molecular system with remarkable spin qubit properties. Its structure offers a higher chemical tunability with respect to archetypal molecular qubits, such as vanadyl(IV)Phthalocyanines (VOPc), and a less rigid organic scaffold where peripheral phenyl rings can promote electron decoupling from the substrate. The properties of a VOTPP monolayer on the Ag(100) surface by photoemission spectroscopies and synchrotron radiation are studied. The results indicate that the electronic and spin features of the massive phase are retained in the monolayer. Moreover, X‐ray photoelectron spectroscopy revealed the existence of two distinct species characterized by varying strengths of molecule‐surface interactions. Like VOPc, these species can be assigned to molecules with the vanadyl group oriented upward or toward the surface. However, in contrast to VOPc, only subtle screening effects are observed in the oxygen‐down configuration, suggesting a more pronounced decoupling effect inherent in the VOTPP structure. This opens broader perspectives for investigations focusing on spin characteristics at the single‐molecule level.

Chaotropic Nanoelectrocatalysis: Chemically Disrupting Water Intermolecular Network at the Point‐of‐Catalysis to Boost Green Hydrogen Electrosynthesis

AbstractEfficient green hydrogen production through electrocatalytic water splitting serves as a powerful catalyst for realizing a carbon‐free hydrogen economy. However, current electrocatalytic designs face challenges such as poor hydrogen evolution reaction (HER) performance (Tafel slope, 100–140 mV dec−1) because water molecules are thermodynamically trapped within their extensive hydrogen bonding network. Herein, we drive efficient HER by manipulating the local water microenvironment near the electrocatalyst. This is achieved by functionalizing the nanoelectrocatalyst's surface with a monolayer of chaotropic molecules to chemically weaken water‐water interactions directly at the point‐of‐catalysis. Notably, our chaotropic design demonstrates a superior Tafel slope (77 mV dec−1) and the lowest overpotential (0.3 V at 10 mA cm−2ECSA), surpassing its kosmotropic counterparts (which reinforces the water molecular network) and previously reported electrocatalytic designs by up to ≈2‐fold and ≈3‐fold, respectively. Comprehensive mechanistic investigations highlight the critical role of chaotropic surface chemistry in disrupting the water intermolecular network, thereby releasing free/weakly bound water molecules that strongly interact with the electrocatalyst to boost HER. Our study provides a unique molecular approach that can be readily integrated with emerging electrocatalytic materials to rapidly advance the electrosynthesis of green hydrogen, holding immense promise for sustainable chemical and energy applications.

Chaotropic Nanoelectrocatalysis: Chemically Disrupting Water Intermolecular Network at the Point-of-Catalysis to Boost Green Hydrogen Electrosynthesis.

Efficient green hydrogen production through electrocatalytic water splitting serves as a powerful catalyst for realizing a carbon-free hydrogen economy. However, current electrocatalytic designs face challenges such as poor hydrogen evolution reaction (HER) performance (Tafel slope, 100-140 mV dec-1 ) because water molecules are thermodynamically trapped within their extensive hydrogen bonding network. Herein, we drive efficient HER by manipulating the local water microenvironment near the electrocatalyst. This is achieved by functionalizing the nanoelectrocatalyst's surface with a monolayer of chaotropic molecules to chemically weaken water-water interactions directly at the point-of-catalysis. Notably, our chaotropic design demonstrates a superior Tafel slope (77 mV dec-1 ) and the lowest overpotential (0.3 V at 10 mA cm-2 ECSA ), surpassing its kosmotropic counterparts (which reinforces the water molecular network) and previously reported electrocatalytic designs by up to ≈2-fold and ≈3-fold, respectively. Comprehensive mechanistic investigations highlight the critical role of chaotropic surface chemistry in disrupting the water intermolecular network, thereby releasing free/weakly bound water molecules that strongly interact with the electrocatalyst to boost HER. Our study provides a unique molecular approach that can be readily integrated with emerging electrocatalytic materials to rapidly advance the electrosynthesis of green hydrogen, holding immense promise for sustainable chemical and energy applications.

Structure affinity of the Langmuir monolayer and the corresponding Langmuir-Blodgett film revealed by X-ray techniques.

The possibility of reproducing the structural organization and functional abilities of a Langmuir monolayer in a film formed from it is one of the fundamental problems of ultrathin film science. This work is devoted to the comparison of monolayer and Langmuir-Blodgett (LB) film characteristics using the example of 2D systems based on the dithia-aza-crown substituted hemicyanine dye HCS. As was shown earlier, the investigated systems are promising for the preparation of selective sensors and extractors for mercury ions in aqueous solutions with a subnanomolar sensitivity threshold. Therefore, the study of the analyte binding mechanism by such a film is of great importance. The study carried out using an ultra-highly brilliant X-ray source (ESRF) allows the application of highly sensitive techniques such as X-ray reflectometry (XRR) and X-ray standing wave (XSW). Comparison of the electron density depth profile of the HCS Langmuir monolayer at the air/water interface and the HCS film transferred to a silicon substrate shows the preservation of the film structure and its functional features. The XSW measurements in turn reveal the similarities in the fine structure of preorganized Langmuir monolayers and Langmuir-Blodgett films of HCS. The integration of X-ray techniques with molecular modeling methods allowed us to show that the crown-ether groups of HCS molecules in the pre-organized monolayer and in the corresponding LB film lie on the surface of water or silicon, and the bound mercury ion is located above the crown-ether, partially binding to the nitrogen atom. The latter loses conjugation to the chromophore group, thereby altering the UV-vis spectrum and providing a response signal. The revealed mechanism of imprinting preorganization allows the proposed approach to be extended to other crown-substituted amphiphilic dyes to significantly enhance the sensory response.

Growth of Chlorine-Doped ZnO Nanorod Arrays on Different Substrates

In this study, zinc nitrate (Zn(NO3)2), hexamethylenetetramine (C6H12N4), and sodium chloride (NaCl) were employed as precursor materials to synthesize ZnO nanorod arrays on two distinct types of substrates using the hydrothermal method. We investigated how different substrates and varying chlorine concentrations influence the synthesis properties of chlorine-doped ZnO nanorod arrays. Specifically, this study aimed to explore the structural, morphological, and optical properties of the synthesized ZnO nanorod arrays. The substrates investigated were an indium tin oxide (ITO) substrate with a ZnO seed layer and an ITO substrate with a self-assembled monolayer (SAM) of molecules. The formation of the SAM involved placing a clean ITO conductive glass substrate into a high-pressure reactor, along with a vial containing 0.2 mm of octadecyltrichlorosilane. Using this process, a uniform SAM was created on the ITO substrate. The molar ratio of Zn(NO3)2, C6H12N4, and NaCl was maintained at 1:1:x, where x varied as 0, 0.1, 0.2, 0.3, and 0.4. This corresponded to NaCl volumes of 0, 2.5, 5.0, 7.5, and 10.0 mM, respectively. The crystallinity and orientation of the nanorods were assessed with their surface morphology using scanning electron microscopy (SEM). By systematically varying the chlorine concentration and substrate type, the role of these parameters was understood in tailoring the characteristics of ZnO nanorod arrays for potential applications in optoelectronic devices, sensors, and photocatalysts.

Langmuir-Blodgett Monolayer of Cobalt Phthalocyanine as Ultralow Loading Single-Atom Catalyst for Highly Efficient H2O2 Production.

The electrochemical production of H2O2 via the two-electron oxygen-reduction reaction (2e- ORR) has been actively studied using systems with atomically dispersed metal-nitrogen-carbon (M-N-C) structures. However, the development of well-defined M-N-C structures that restrict the migration and agglomeration of single-metal sites remains elusive. Herein, we demonstrate a Langmuir-Blodgett (LB) monolayer of cobalt phthalocyanine (CoPc) on monolayer graphene (LB CoPc/G) as a single-metal catalyst for the 2e- ORR. The as-prepared CoPc LB monolayer has a β-form crystalline structure with a lattice space for the facile adsorption of oxygen molecules on the cobalt active sites. The CoPc LB monolayer system provides highly exposed Co atoms in a well-defined structure without agglomeration, resulting in significantly improved catalytic activity, which is manifested by a very high H2O2 production rate per catalyst (31.04 mol gcat-1 h-1) and TOF (36.5 s-1) with constant production stability for 24 hours. To the best of our knowledge, the CoPc LB monolayer system exhibits the highest H2O2 production rate per active site. This fundamental study suggests that an LB monolayer of molecules with single-metal atoms as a well-defined structure works for single-atom catalysts.

Molecular dynamics study on BS12/SDS stabilized CO2 foam: Evaluation of surfactant monolayer structure and interfacial properties

CO2 foam flooding holds great potential for enhanced oil recovery and geological storage. However, ensuring the stability of supercritical CO2 foam systems under high temperature and pressure reservoir conditions remains a challenge. Note that the term "supercritical CO2 foam" specifically denotes a foam system created by combining an aqueous solution containing chemical additives with CO2 in a supercritical state under high-temperature and high-pressure conditions. Surfactants can reduce the surface Gibbs free energy by adsorbing onto the CO2-water interface to form a monolayer structure, which hinders CO2 diffusion and improves foam stability. In this study, molecular dynamics simulations were employed to analyze the adsorption behavior and interfacial performance of betaine surfactant BS12 and the anionic surfactant SDS at the CO2-water interface. The results indicate that BS12 can reduce interfacial tension more effectively at near-saturated concentrations. Moreover, the monolayer formed by BS12 has a lower voidage and wider interfacial thickness. The carboxyl-nitrogen interaction among BS12 molecules impedes their further aggregation, thereby maintaining the mutually perpendicular "L" orientation of the headgroup and hydrophobic tail thus forming a rigid and stable monolayer structure. Additionally, the spatial distribution function, radial distribution function, and hydrogen bond statistics indicate that although BS12 exhibits slightly weaker hydrophobicity than SDS, its hydrophobicity is less affected by concentration. Specifically, the first hydration shell of the carboxyl group remains stable even at high concentrations. Besides, the steered simulations show that the rate-limiting step in the CO2 permeation process is the dense region of the surfactant headgroups. Besides, the permeation of CO2 molecules in the BS12 monolayer is characterized by a lower diffusion coefficient and higher energy barrier to overcome. In summary, BS12 forms a thicker and more uniform monolayer structure, effectively hindering the contact between CO2 and water molecules at the interface and further enhancing foam stability. Our findings further reveal the relationship between surfactant molecular architecture and interfacial properties, providing references for the screening and structural design of surfactants used in CO2 foam flooding.

Study of Formation and Properties of F4TNCQ/MoS2 Heterostructures with point defects driven by DFT and Neural Network Potential

State-of-the-art computational techniques allow us to perform the comprehensive investigation of organic/inorganic heterostructures based on F4TCNQ molecule and MoS2 monolayer. The features of electronic and optical properties with the presence of point defects at MoS2 surface were studied. We found that halogen impurities lead to strengthening of organic/inorganic interface. Based on variation of the binding energy between F4TCNQ and MoS2 surface the neural network potential was trained with the aim to study the possibility of formation of monomolecular layer. Molecular dynamics calculation shows the anchoring behavior of F4TCNQ molecule in a position of sulfur vacancy with the same binding energy as in case of halogen doping. Present results show advantages of defect creation in MoS2 surface with the aim to control the ordering of monomolecular layer and the properties of the whole heterostructure. We show the first fundamental step of using organic/inorganic heterostructures for application in optoelectronic sensors and detectors.

Design of a simple bifunctional system as a self-assembled monolayer (SAM) for inverted tin-based perovskite solar cells

In this work, we functionalized the ITO substrates with a series of self-assembled monolayer (SAM) molecules to improve the hole extraction ability of the electrodes and retard the charge recombination with the devices in an inverted planar p-i-n configuration. Organic molecules with simple structures, namely 4-aminobenzoic acid (AB), 4-(2-aminomethyl)benzoic acid (AM), 4-(2-aminoethyl)benzoic acid (AE), and 4-nitrobenzoic acid (NB) were chosen to functionalize the ITO substrates via simple immersion method to form hole-selective SAM on ITO. The TPSCs were fabricated according to a two-step sequential deposition approach using a co-solvent system, and the AB device was found to exhibit an attractive efficiency of power conversion (PCE) of 7.6 % while the other SAM-based devices showed poorer performance. The AB device also displayed impressive long-term storage stability by maintaining about 80 % of its initial efficiency for over 3500 h without encapsulation, in addition to a long-term (6 h) light-soaking stability, which is superior to the PEDOT: PSS-based device in ambient conditions. The SAM/perovskite interfacial characteristics were studied using UPS, EIS, and TCSPC to understand the energy levels, charge recombination, and hole-extraction nature, respectively, and to support the outstanding performance and stability of the AB device.

Atomic regulation to improve the sensing-performance of CoPc and NiPc monolayer toward chloromethane molecule: Insights from DFT calculations

The development of a high-performance gas sensor for efficient detection of harmful chloromethane (CH3Cl) is of great importance to environmental monitoring and human health. Herein, the density functional theory (DFT) method was employed to compare the adsorption behaviors and electronic properties of CH3Cl on two-dimensional monometal modified phthalocyanines (CoPc, NiPc) and metal dimer modified phthalocyanines (CoTMPc and NiTMPc, TM = Ti∼Zn) surfaces. The studied results indicate that the CoPc and NiPc monolayers are not suitable as gas-sensitive materials for the detection of CH3Cl molecule due to their weak adsorption ability and low sensitivity. However, the adsorption strength and electronic properties of single-layer CoTMPc and NiTMPc towards CH3Cl can be effectively regulated through the synergistic effect of bimetallic species. Among them, the CoVPc, Co2Pc, NiVPc and NiZnPc monolayers exhibit moderate affinity for CH3Cl molecule, with the adsorption energies of −0.84 eV, −0.62 eV, −0.89 eV and −0.54 eV, respectively. The microscopic interaction mechanisms between CH3Cl molecule and bimetallic phthalocyanine monolayers are revealed through the analyses of total charge density, charge density difference and density of states. Furthermore, significant changes in bandgap are observed for Co2Pc and NiZnPc upon CH3Cl adsorption, while CoVPc and NiVPc monolayers exhibit noticeable variations in magnetic moments, indicating their high sensitivity towards CH3Cl. Considering the balance of adsorption strength, sensitivity and recovery time, the CoVPc, Co2Pc, NiVPc and NiZnPc monolayers are regarded as a great potential as gas-sensitive materials for recyclable CH3Cl gas sensors.

Study Of Using Bentonite – Poly Ethylene Glycol Composite for Metal Removal from Water

Direct polymerization of polyethylene glycol (PEG) in suspensions of Bentonite (Ben) was used for preparation of Ben-PEG composite. The prepared composite was characterized using field-effect scanning electron microscopy, surface area measurements, and X-ray diffraction. In the XRD pattern there is a change in peak intensity. But New peaks appeared. This may be due to high dispersion of particles of polymer in the Ben matrix or low concentration of the modifying agent. The crystallinity absence after loading the sorbent with cadmium and lead ions in the SEM measurement indicates that there was no crystalline phase after sorption. The optimal conditions for adsorption of Cd2+ and Pb2+ ions were found to be a PEG content of 0.2 % and a contact time of 150 min. The sorption experiments were performed under different operating variables, including, pH, adsorbent dose and initial concentration of metals. For both Cd2+ and Pb2+, Adsorption parameters were determined using both Langmuir and Freundlich isotherms, but the experimental data were better fitted to the Langmuir equation than to Freundlich equation. The adsorption equilibrium was described by the Langmuir model, which confirmed the presence of saturated mono-layer of adsorbent molecules on the adsorbent surface, that the energy of adsorption is constant. The potential of Ben-PEG composite for the removal of cadmium and lead from aqueous solution was substantiated.

High performance mechano-optoelectronic molecular switch

Highly-efficient molecular photoswitching occurs ex-situ but not to-date inside electronic devices due to quenching of excited states by background interactions. Here we achieve fully reversible in-situ mechano-optoelectronic switching in self-assembled monolayers (SAMs) of tetraphenylethylene molecules by bending their supporting electrodes to maximize aggregation-induced emission (AIE). We obtain stable, reversible switching across >1600 on/off cycles with large on/off ratio of (3.8 ± 0.1) × 103 and 140 ± 10 ms switching time which is 10-100× faster than other approaches. Multimodal characterization shows mechanically-controlled emission with UV-light enhancing the Coulomb interaction between the electrons and holes resulting in giant enhancement of molecular conductance. The best mechano-optoelectronic switching occurs in the most concave architecture that reduces ambient single-molecule conformational entropy creating artificially-tightened supramolecular assemblies. The performance can be further improved to achieve ultra-high switching ratio on the order of 105 using tetraphenylethylene derivatives with more AIE-active sites. Our results promise new applications from optimized interplay between mechanical force and optics in soft electronics.

Understanding the sources of mercury release from coal: A combined experimental and molecular simulation study

Understanding the occurrence modes of mercury in coal is important as its release poses long-term adverse effects on the environment and human health during coal production and utilization. However, the matter still remains a subject of controversy due to differing results from direct and indirect analyses, which suggest various possible modes of occurrence for mercury in coal. Additionally, the experimental measurement of Hg concentration presents challenges, further contributing to the complexity of the issue. A comprehensive investigation of experiments and molecular simulations is conducted herein. Electron probe microanalysis and elemental mapping analysis show that elemental Hg is concentrated in framboidal pyrites while absent in organic matter. To understand the occurrence modes of mercury in inorganic and organic materials at the atomic level, molecular simulations are performed for Hg2+ adsorption and retention in MMT, pyrite, and kerogen slit nanopores. It is found that the inorganic MMT and pyrite surfaces have a greater adsorption capacity than the organic kerogen surface (pyrite > MMT > kerogen). The outer-sphere adsorption is mainly observed with at least one monolayer of water molecules exiting between the ion and mineral surfaces. MMT has the highest retention for Hg2+ transport as the self-diffusion coefficient is the smallest among the three slit pores (MMT < pyrite < kerogen). The high adsorption and retention originate from the strong Hg2+-mineral interaction. These results suggest that mercury in coal is most likely associated with inorganic minerals instead of organic matter.

Interaction between peptides and an MoS2 monolayer containing a nanopore: First-principles calculations

• The reaction between small peptide molecules and the MoS2 nanopore are explored: • Serine and Glycylglycine don't have any bonding and interaction with MoS2/NP. Each plays the role of a passer in the system. • Two dipeptides, Aspartame and Carnosine, and the tripeptide Glutathione react with Mo and S atoms surrounding the hole and form stable compounds. First-principles density functional theory (DFT) is employed to explore the interaction between a peptide molecule and two-dimensional (2-D) monolayer of molybdenum disulfide (MoS 2 ) containing a nanopore. A variety of monopeptides, dipeptides and also a tripeptide are individually positioned in the hole of a MoS 2 layer and the overall electronic structure calculated. The results indicate that bonding occurs between some molecules and the hole edge. The outcome of reaction can be predicted through the potential energy surface. These results strongly suggest that 2-D MoS 2 nanopores have a wide range of biological applications and deserve further exploitation by experiment.

Surfactant micellar induced aggregation control of an anionic fluorescent dye in Langmuir-Blodgett film

This work reports the formation of stable Langmuir monolayer of an anionic water soluble fluorescent dye 5(6)-carboxyfluorescein (abbreviated as CFS) by electrostatic interaction with a cationic monolayer. Formation of non-fluorescent H-dimeric sites of CFS molecules in Langmuir monolayer and Langmuir Blodgett films has been controlled by using cationic surfactant micelles of cetyltrimethylammonium bromide (CTAB). Thus the film can act as efficient fluorescence marker. Langmuir monolayer has been investigated by Surface Pressure versus Area per molecule (π-A) isotherm and in situ Brewster Angle Microscope (BAM) studies. Mono and multilayered Langmuir Blodgett films were characterized by using UV–vis absorption and steady state fluorescence spectroscopy.

Spin‐Crossover Grafted Monolayer of a Co(II) Terpyridine Derivative Functionalized with Carboxylic Acid Groups

AbstractThe synthesis and characterization of a new Co(II) spin‐crossover (SCO) complex based on 4′‐(4‐carboxyphenyl)−2,2′:6′,2″‐terpyridine ligand are reported. This complex can be successfully grafted on silver surface maintaining the SCO behavior. Thus, atomic force microscopy (AFM), matrix assisted laser desorption ionization – time‐of‐flight mass spectrometry (MALDI‐TOF MS), Raman spectroscopy, and XPS measurements, upon surface deposition, evidence the formation of a monolayer of intact molecules grafted through carboxylate groups to the Ag surface. Three different techniques: Raman spectroscopy, X‐ray photoelectron spectroscopy (XPS), and X‐ray absorption spectroscopy (XAS), supported by first‐principles calculations, confirm that the deposited molecules undergo a gradual spin transition with temperature. This phenomenon is unprecedented for a monolayer of molecules directly grafted onto a metallic surface from solution.

Amperometric Detection of NH3 by Aromatic SAM-Modified Graphene

Ammonia (NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) is a toxic substance resulting in various acute and chronic effects on individuals. NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> detection, monitoring methods, and detection tools are desperately needed. In this work, we improved the ammonia sensing capabilities of graphene films deposited by chemical vapor deposition (CVD) by modifying aromatic self-assembled monolayer (SAM) molecules such as 5-[(3-methylphenyl) (phenyl) amino] isophthalic acid (MeIPA) and 5-(diphenyl)amino] isophthalic acid (PhIPA) on amperometric detection method. Morphological investigations of the films were carried out by optical and scanning electron microscopy (SEM). Surface potential was characterized with Kelvin Probe Force Microscopy (KPFM), and vibrational properties were characterized with Raman Spectroscopy. MeIPA modification increased NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> uptake by two times compared to unmodified graphene. The results indicated that the SAM modification enhanced NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> molecule adsorption and improved its periodic reversible and reproducible response using the amperometric detection system, indicating that SAM molecules might be a feasible probe for ammonia.