Near-infrared Absorption Spectroscopy Research Articles

Development and optimisation of a near-infrared spectroscopic system for glucose quantification in aqueous and intralipid-based samples

A non-invasive glucose sensing device could revolutionise diabetes treatment. Near Infrared (NIR) spectroscopy is a promising technology for glucose sensing; however, the design and choice of components for NIR spectroscopy can greatly affect the sensing accuracy. We aimed to develop a NIR absorption spectroscopy system to determine liquid glucose concentrations in the physiological range, by evaluating a range of NIR photodetector components and light sources. Three detection assemblies were tested: (i) a dispersive spectrometer with photodiode array, (ii) a Czerny–Turner monochromator with InGaAs photodiode and (iii) a miniature Fourier Transform Infrared (FTIR) spectrometer. A halogen lamp and NIR globar were trialled as potential light sources. The components were systematically tested by comparing the coefficient of determination and standard error of prediction (SEP) for the same set of aqueous glucose samples through 10 mmol l−1 concentration steps. The Czerny–Turner monochromator with InGaAs photodiode, along with the globar, were identified as the optimal components for the system. A range of concentration steps (1–10 mmol l−1) were scanned to identify the physiologically relevant limit of detection, which was identified as 5 mmol/l for glucose in solution. Spectra were then collected from glucose samples in 10% intralipid suspension in the 10–20 mmol l−1 range and the equivalent concentrations in solution. The SEP was greater for the intralipid samples due to strong scattering. Scattering was dominant above 1300 nm, whilst absorption was dominant below 1300 nm. Although alternative approaches achieve better resolution, our system uses simple and readily-available components and presents a platform for a non-invasive NIR glucose sensing device.

Silicon rib waveguide with palladium coated gold nanorods overlayer for hexane and N-methylaniline detection

The adsorption of hexane and N-methylaniline was investigated by on-chip vibrational spectroscopy. The interaction with the Pd surface significantly perturbs the vibrational modes of hexane. Near-infrared absorption spectroscopy on the waveguide detected a redshifted CH stretching vibration. We showed that while rapid evaporation of one component may occur, the modification facilitates the sensing for large molecules and mixtures of substances. Rib waveguides were modified with palladium to exhibit an enhanced electromagnetic field effect due to the electrostatic interaction of Pd and hydrogen, showing the drop in the amine overtone absorption of 7.6 dB and the overtone related to the bond of carbon to hydrogen of 6.8 dB. The absorption of hexane bonds in water is 5.5 dB. The obtained values are 100 times higher than those predicted by the electromagnetic simulator for pure rib waveguides. This may be explained by CH bonds in hexane that can be activated through a hydrogen bond-like interaction with metal substrates. This achievement holds promising potential for advancing hexane and N-Methylailine detection and analysis technologies, with implications for diverse applications in various industries, such as environmental monitoring, industrial processes, and safety measures.

Near-Infrared Laser Methane Remote Monitoring Based on Template Matching Algorithm of Harmonic Signals

Trustworthy technology for the monitoring of fugitive methane emissions is an indispensable component for low−carbon emission reduction and safe production in oil and gas infrastructure. A miniaturization and low-cost methane remote monitoring prototype based on near-infrared laser absorption spectroscopy is developed to retrieve the path−integral concentration by employing the harmonic conjoint analysis method for the backscattered echo signals from a distant non-cooperative target. A distorted harmonic template matching (DHTM) algorithm is proposed based on wavelength modulation spectroscopy with second harmonic normalized via the first harmonic (WMS−2f/1f) method, which suppresses the output concentration fluctuation caused by open path monitoring with non-cooperative target and avoids the issue of false alarms during the detection process without target gas. The reliability of the WMS−2f/1f−DHTM algorithm is verified by calibration and dynamic experiments. The results showed that this algorithm avoids the dilemma of false alarms in the absence of gas compared to the conventional WMS−2f/1f algorithm, while the root mean square error (RMSE) of the concentration inversion with a detection distance of 20 m is reduced by 57.6% compared to direct absorption spectroscopy (DAS) algorithm. And the minimum detection limit of system is 3.79 ppm·m. The methane telemetry sensor with the WMS−2f/1f−DHTM algorithm exhibits substantial application potential in carbon monitoring of oil and gas industry.

Ultraviolet Resonance Raman Spectra of Serum Albumins.

The ultraviolet resonance Raman (UVRR) spectra of the two proteins bovine serum albumin (BSA) and human serum albumin (HSA) in an aqueous solution are compared with the aim to distinguish between them based on their very similar amino acid composition and structure and to obtain signals from tryptophan that has only very few residues. Comparison of the protein spectra with solutions of tryptophan, tyrosine, and phenylalanine in comparative ratios as in the two proteins shows that at an excitation wavelength of 220 nm, the spectra are dominated by the strong resonant contribution from these three amino acids. While the strong enhancement of two and one single tryptophan residue in BSA and HSA, respectively, results in pronounced bands assigned to fundamental vibrations of tryptophan, its weaker overtones and combination bands do not play a major role in the spectral range above 1800 cm-1. There, the protein spectra clearly reveal the signals of overtones and combination bands of phenylalanine and tyrosine. Assignments of spectral features in the range of Raman shifts from 3800 to 5100 cm-1 to combinations comprising fundamentals and overtones of tyrosine were supported by spectra of amino acid mixtures that contain deuterated tyrosine. The information in the high-frequency region of the UVRR spectra could provide information that is complementary to near-infrared absorption spectroscopy of the proteins.

Enhancement of the Lowering Effect on Energy Levels of LUMO by the Formation of B−N Dative Bond for Near‐infrared Light Absorption Properties Based on 1,3,4,6,8,9 b‐Hexaazaphenalene

AbstractWe illustrate the development of 1,3,4,6,8,9b‐hexaazaphenalene (6AP) derivatives which exhibit excellent near‐infrared (NIR) light absorption properties and deep LUMO levels. The electron‐withdrawing character of the 8‐nitrogen atom in the 6AP scaffold was enhanced by the introduction of a B−N dative bond. This formation of a boron‐nitrogen Lewis acid‐base pair succeeded in strengthening the electron‐withdrawing ability of the 8‐nitrogen atom, which induced the low‐lying LUMO levels of the resultant boron complexes. The data from UV−vis−NIR absorption spectroscopy and cyclic voltammetry suggested that these deep LUMO levels were the origins of the narrow HOMO−LUMO gap caused by selectively lowering the LUMO energy level. Furthermore, the enhancement of the molar absorption coefficients was observed in the boron complex compared to other azaphenalene derivatives in the previous reports. From theoretical calculations, the electron‐withdrawing character of the 8‐nitrogen atom induced the weak but substantial delocalization of the LUMO into the 7,9‐positions, where the LUMOs of other azaphenalene derivatives hardly exist. This electronic effect could influence the intrinsic symmetry forbidden character of electronic transition between the HOMO and the LUMO, resulting in the larger molar absorption coefficients by partially transforming to the allow character compared to those of other azaphenalene derivatives. In summary, the introduction of the boron‐nitrogen Lewis acid‐base pair into the π‐conjugated system of azaphenalene afforded the NIR light absorption properties with the ϵ reaching ∼104 M–1cm–1 and the deep LUMO levels around −4.0 eV (estimated by cyclic voltammetry).

Temperature and anion ligand field dependence of LnCl3 (Ln = Nd, Dy, Sm) electronic absorption spectra in LiCl–KCl eutectic molten salt

A comprehensive knowledge of the coordination, bonding, and speciation of elements in molten salt mixtures is necessary to understand and predict the chemical and physical properties of the salt. Absorption spectroscopy can yield information about the chemistry of species of interest in alkali halide molten salt mixtures by revealing information about the electronic structure and transitions of those species. In this study, ultraviolet (UV), visible (vis), and near-infrared (NIR) absorption spectroscopy was used to examine changes to the electronic structure of trivalent Nd, Sm, and Dy in LiCl–KCl eutectic molten salt with changes in temperature and the anion composition of the melt. With increasing temperature, changes to spectral features suggest a distortion of the coordination complexes. Changes to lineshape with the substitution of alternative halide anions were examined and analyzed, revealing differences in the coordination for I− versus F− with the lanthanides. Gaussian peak fitting was used to show that the changes in lineshape with the progressive addition of F− anions can be explained by the superposition of a set of absorption bands from complexes with all Cl− anion ligands and a set of blueshifted absorption bands from complexes containing both F− and Cl− anion ligands. This work yields a new method to analyze and interpret change to electronic absorption spectra for f-block elements dissolved in alkali halide molten salts as well as new observations of the interactions of larger and smaller halide anions with lanthanides in Cl−-based molten salts.

Application of Linear Additive Conditions for Near-Infrared Diffuse Reflectance Absorption Spectroscopy

Determining the homogeneity of material mixing in real time during product processing is critical for quality control. According to the Kubelka–Munk (K-M) function of diffuse reflectance absorption spectrum, absorbance (A) is approximately linear with the content of the components when the sample scattering coefficient (S) is in a certain range. The S is determined by the particle size of powder samples. Therefore, this study determined particle size ranges that satisfy linear additivity in near-infrared diffuse reflectance spectroscopy (NIRDRS). Thus, the proposed NIRDRS analysis technique can be used to determine the homogeneity of material mixes or analyze the percentages of the components in the mixture. In this study, vitamin B3 and vitamin C were used for preparing mixed samples with varying percentages. The experimental results revealed that linear additivity is satisfied when the powder particle size is in the range of less than 280, 280–450, and 450–900 μm. When the confidence level is 0.01, the actual mixed spectra are not significantly different from the “simulated mixed spectra” constructed by linear addition, with their relative deviations less than 1.08%. The absolute errors of the actual and analytic percentages were within 2.98% for each component in the mixtures. The above conclusions also hold for sorghum, which has a complex material composition. Statistical models cannot analyze the percentages of components in the mixture. In contrast, linear addition and direct calibration approach avoids the use of a large number of samples for statistical modeling and analyze the percentages of mixed samples. Meanwhile, it can be used to discriminate and analyze the material mixing uniformity by building a mechanistic model.

Preparation, Characterization, and In Vitro Evaluation of Inclusion Complexes Formed between S-Allylcysteine and Cyclodextrins.

The present study prepared inclusion complexes of S-allylcysteine (SAC) and cyclodextrin (α, β, γ) by the freeze-drying (FD) method and verified the inclusion behavior of the solid dispersion. Also, the study investigated the effect of SAC/CD complex formation on liver tumor cells. Isothermal titration calorimetry (ITC) measurements confirmed the exothermic titration curve for SAC/αCD, suggesting a molar ratio of SAC/αCD = 1/1, but no exothermic/endothermic reaction was obtained for the SAC/βCD and SAC/γCD system. Powder X-ray diffraction (PXRD) results showed that the characteristic diffraction peaks of SAC and CDs disappeared in FD (SAC/αCD) and FD (SAC/γCD), indicated by a halo pattern. On the other hand, diffraction peaks originating from SAC and βCDs were observed in FD (SAC/βCD). Near-infrared (NIR) absorption spectroscopy results showed that CH and OH groups derived from SAC and OH groups derived from αCD and γCD cavity were shifted, suggesting complex formation due to intermolecular interactions occurring in SAC/αCD and SAC/γCD. Stability test results showed that the stability was maintained with FD (SAC/αCD) over FD (SAC/βCD) and FD (SAC/γCD). In 1H–1H of NOESY NMR measurement, FD (SAC/αCD) was confirmed to have a cross peak at the CH group of the alkene of SAC and the proton (H-3, -5, -6) in the αCD cavity. In FD (SAC/γCD), a cross peak was confirmed at the alkyl group on the carbonyl group side of SAC and the proton (H-3) in the cavity of γCD. From the above, it was suggested that the inclusion mode of SAC is different on FD (SAC/CDs). The results of the hepatocyte proliferation inhibition test using HepG2 cells showed that FD (SAC/βCD) inhibited cell proliferation. On the other hand, FD (SAC/αCD) and FD (SAC/γCD) did not show a significant decrease in the number of viable cells. These results suggest that the difference in the inclusion mode may contribute to the stability and cell proliferation inhibition.

Multi-parameter methane measurement using near-infrared tunable diode laser absorption spectroscopy based on back propagation neural network

In order to achieve high-precision and continuous measurement of methane (CH4) isotope abundance (δ13CH4), a near-infrared CH4 sensor system was developed based on back propagation (BP) neural network using tunable diode laser absorption spectroscopy (TDLAS). A pair of CH4 isotope absorption lines with similar low-state energy levels near 1658 nm were selected for minimizing temperature dependence. A LabVIEW-based signal processing platform was realized for real-time signal processing. Wavelet denoising (WD) algorithm was employed to pre-process the absorption signal for increasing signal-to-noise ratio (SNR), and the BP neural network algorithm was adopted to invert δ13CH4. The BP neural network algorithm exhibits potential for multi-parameter analysis, including gas temperature and pressure. Related experiments were carried out to prove the high-precision and reliability of the neural network inversion method. Through experimental comparison, the measurement precision of δ13CH4 is enhanced by ∼ 11 times using the neural network inversion method compared to the maximum absorbance extracting method.

Ligand Modified and Light Switched On/Off Single-Chain Magnets of {Fe 2 Co} Coordination Polymers via Metal-to-Metal Charge Transfer

Ligand Modified and Light Switched On/Off Single-Chain Magnets of {Fe ₂ Co} Coordination Polymers via Metal-to-Metal Charge Transfer

Carbon Nanotube Liquid Crystal Dispersion for Large-Area, Micropatterned Aligned Films

Aligned single-walled carbon nanotube (SWCNT) films are potential materials for devices with excellent electrical and optical properties. However, the fabrication of well-aligned SWCNT films is limited, along with practical issues such as the area size and mass production. In this study, we successfully developed a method to fabricate SWCNT films with high alignment by applying an SWCNT dispersion to a substrate using a general wet-coating technique. The prepared SWCNT film showed a high degree of orientation with a nematic order parameter of 0.86 and 0.56 based on Raman spectroscopy and near-infrared (NIR) absorption spectroscopy, respectively. An orientation film several tens of centimeters in length can be prepared on polyethylene terephthalate (PET) film by wet-coating and drying. Furthermore, using the photoresponsive property of the dispersant, micrometer-scale patterning is also possible. The proposed method paves the way for the development of SWCNT-aligned devices for electronic and optical applications, such as the NIR/infrared polarizer and the detector and the electrode.

A sensitive carbon monoxide sensor for industrial process control based on laser absorption spectroscopy with a 2.3 μm distributed feedback laser

Carbon monoxide (CO) is a ubiquitous atmospheric trace gas produced by natural and anthropogenic sources. It can be used as a quantitative marker to help us understand the different production processes. A near-infrared laser absorption spectroscopy of 2.3 μm based in-situ, real-time and continuous CO sensor equipment is developed for the exhaust pipeline of furnace. High sensitivity is accomplished utilizing the ratio between the second and first harmonic signals detection (WMS-2f/1f). The analyzer is housed in an explosion-proof enclosure and installed at both sides of the pipeline with a diameter of 2.1 m. The measured gas temperature inside the pipeline reaches around 400 K. The results primarily show a more linear response and less error, the measurement precision and the minimum detection limit are 0.42 ppm and 1.29 ppm (1σ), simultaneously. Evaluation of the data suggested a dynamic range from 3.87 ppm to 1.3% based on the 3σ rule and maximum absorbance of one. An operator can analyze the industrial production process clearly, that is, the measured CO concentration is negatively correlated with excess oxygen (O2) by observing the measurement results within 10 h. Meanwhile, the measurements of the real targets show that the sensor has great applicability and potential for exhaust pipeline and combustion control systems.

Methane near-infrared laser remote detection under non-cooperative target condition based on harmonic waveform recognition

A 2f/1f signal processing technique with harmonic waveform recognition method is proposed. The proposed method is used in the methane near-infrared laser remote detection system to solve the instability problems caused by the amplitude fluctuation and the deformation of the harmonic signal during the methane remote sensing under non-cooperative target conditions. The methane remote sensor system based on near-infrared tunable diode laser absorption spectroscopy (TDLAS) and improved WMS-2f/1f method is developed. The laser transmission characteristics under non-cooperative target conditions were analyzed using Monte Carlo ray tracing method. The linear relationship (R2 = 0.9969) fitted by experimental data between the amplitude of 2f/1f signal and methane concentration. The stability test and Allan deviation analysis of methane TDLAS telemetry sensor is conducted. The results illustrate that a minimum detection limit (MDL) of 2.66 ppm·m for the improved WMS-2f/1f method is obtained with the averaging time of 273.8 s. The MDL is significantly lower than the conventional WMS-2f/1f method. The experimental results verify that the improved WMS-2f/1f method is adopted to reduce the signal fluctuation influence and improve the detection stability.

Preparation and Characterization of a Hybrid Complex of Cyclodextrin-Based Metal-Organic Frameworks-1 and Ascorbic Acid Derivatives.

Cyclodextrin-based metal–organic frameworks-1 (CD-MOF-1) prepared using potassium hydroxide, ethanol, and γ-cyclodextrin (γ-CD) has been reported as a new type of MOF for the development of pharmaceutical formulations. The present study aimed to investigate the physicochemical properties of ascorbic acid derivatives (L-ascorbyl 6-palmitate (ASCP); L-ascorbyl 2,6-palmitate (ASCDP)) complexed with CD-MOF-1 by a solvent evaporation method. Powder X-ray diffraction revealed that the crystal diffraction pattern of CD-MOF-1 changed from α-type to β-type when prepared by a solvent evaporation method. For ASCP/CD-MOF-1 = 1/2 and ASCDP/CD-MOF-1 = 1/4 evaporated samples, the crystal diffraction peaks derived from ASCP and ASCDP disappeared, indicating a β-like behavior. Differential scanning calorimetry results revealed that the endothermic peaks of evaporated samples (ASCP/CD-MOF-1 = 1/2 and ASCDP/CD-MOF-1 = 1/4) were not detected due to melting. Furthermore, intermolecular interactions were observed in the hydrogen bonds between the CH groups of the side chains of ASCP and ASCDP and the OH group of CD-MOF-1 in (ASCP/CD-MOF-1 = 1/2) and EVP (ASCDP/CD-MOF-1 = 1/4), based on the near-infrared absorption spectroscopy analysis. CD-MOF-1 did not form inclusion complexes with the lactone rings of ASCP and ASCDP, but with the lipophilic side chains. These results suggested that CD-MOF-1 may be useful in preparing novel drug carriers for ASCP and ASCDP.

PV modules and their backsheets - A case study of a Multi-MW PV power station

Degradation of backsheets (BSs) and encapsulant polymer components of silicon PV modules is recognized as one of the main reasons for losses in PV plant performance and lifetime expectations. Here, we report initial insights into the correlation between BS composition of PV-modules and PV power station performance by using a combination of lab- and field-imaging, as well as spectroscopic and electrical characterizations. Using field-suitable near-infrared absorption (NIRA) spectroscopy, the BS structure of 518 PV-modules, 2.5 % of the PV-modules in a 5 MWp PV power station, was identified on-site. The variance of the BS composition was found to be heterogeneous across PV-modules of the same power class from the same manufacturer. Polyamide-based BSs cause in 10 out of 100 inverters ground impedance values below 400 kΩ, which is a typical threshold for inverters connecting to the grid. For fluorinated coating-based BSs this low value is reached 20 times. We conclude these numbers best as possible from the available monitoring data of inverters associated with BS-types from NIRA. The identification of degraded coating-based BSs is challenging, since visually they look healthy and undistinguishable to well performing BSs. The present results demonstrate that a deeper understanding of the relationship between bill-of-materials and performance of PV-modules is necessary to avoid/minimize inverter shut-downs, and that it can be achieved by using combinations of selected field and lab characterization methods with monitoring data. • Analyzing backsheets of 518 PV-modules in the field using near-infrared spectroscopy. • Distinguishing various backsheet types: polyamide, PVF-PET-PE, PVDF-PET-PE, FC-PET-PP. • Leakage resistance loss rate differs strongly for FC-based and PA-based BSs. • Monitoring data of inverter indicate different loss of ground impedance associated with differing BS material. • Inverter shut-down are observed at least twice as often in inverters with FC-based BS as in those with PA-based BS.

Time-resolved dual-comb spectroscopy with a single electro-optic modulator.

Time-resolved near-infrared absorption spectroscopy of single non-repeatable transient events is performed at high spectral resolution with a dual-comb interferometer using a continuous-wave laser followed by a single electro-optic amplitude modulator. By sharing high-speed electrical/optical components, our spectrometer greatly simplifies the implementation of dual-comb spectroscopy and offers a high mutual coherence time, measured up to 50 s, without any active stabilization system and/or data processing. The time resolution is as short as 100 µs in our experimental demonstration. For a span of 36 GHz, the mean signal-to-noise ratio of 80, at 100-MHz spectral resolution and 100-µs measurement time, enables precise determination of the parameters of rovibrational lines, including intensity or concentration.

In-situ laser detection of water vapor based on circular prism array multi-pass cell enhanced near-infrared absorption spectroscopy

In-situ detection of water vapor concentration is a vital procedure in the monitoring framework of energy exploitation and transportation for oil and gas industry. A water vapor sensor system using direct absorption spectroscopy was developed based on a novel circular prism array multi-pass cell (CPA-MPC). The optimal optical path of 12-star-polygon pattern was determined by fuzzy comprehensive evaluation (FCE) method. The polarization disturbance noise in output laser intensity was analyzed based on polarization theory. The CPA-MPC yields an effective optical path length of 173.9 cm within a compact annular-volume of 217 mL. A laboratory test of the CPA-MPC based laser sensor system shows that the relative error of average H2O concentration is 2.87% in ambient air. SNR of the sensor achieves to 608.3, which constitutes a 13-fold improvement compared to opposite-type laser detection. Allan deviation analysis indicates that minimum detection limit of 7.09 ppm is achieved with a 216 s averaging time. In order to verify the application potential of the proposed CPA-MPC based laser sensor system in industrial field, a dynamic in-situ monitoring experiment is performed. And the typical thermodynamic phenomena of liquid water heated evaporation is successfully captured in the alternation between opening state and sealing state.

High-speed supercontinuum laser absorption spectroscopy of light hydrocarbons in elevated pressures and temperatures

10 kHz near-infrared supercontinuum laser absorption spectroscopy measurements of methane (CH4) and acetylene (C2H2) were demonstrated. Measured absorption spectra were processed using the HITRAN database to infer species concentrations and temperatures. High pressure and high temperature measurements up to 10 bar and 800 K, respectively, were made in dedicated optical cells. Reacting flow field was also probed over a 6 cm flat flame burner. Due to the very short pathlength over the burner surface, a toroidal multipass reflection cell was used to maximize measurement sensitivity. The multipass cell was designed specifically to withstand high temperature environment around the flat flame burner and supported multiple beam pathlength configurations. The beam paths within the cell exist on a thin plane and were used to measure temperatures at various heights above the burner surface. Despite relatively low signal-to-noise ratio at higher temperature environments, species concentration predictions agreed well with experiment conditions. Temperature results agreed well with simulated results to within 20.2 K in the preheat zone of a methane–air flame.

Optical design of dual-elliptical mirrors of near-infrared absorption spectroscopy for diabetes detection

An optical design model of dual-elliptical mirrors near-infrared absorption spectroscopy (NIRAS) for detection of diabetes is proposed. This design model improves the optical efficiency of the conventional NIRAS system without the use of optical components. We used the Henyey–Greenstein scattering skin model in the simulation to calculate the light scattering phenomena. Based on the virtual skin model, the dual-elliptical mirrors NIRAS system can focus the light-emitting diode (LED) light into deeper depths of the human skin and collect more backscattered light. The dual-elliptical mirrors NIRAS system can enhance the light collection efficiency by 1.6 times that of the conventional NIRAS system and 66 times that of the dual-elliptical lens NIRAS system. In terms of assembly tolerance, the normalized light collection efficiency (LCE) of LED and photodiode can be maintained above 0.9 and 0.68, respectively, at a 0.2-mm displacement. The LCEs of the φ and θ rotations are at least 0.95 with a 5-deg tilt error of the chips.

Clay coatings on sands in the western Qaidam Basin, Tibetan Plateau, China: Implications for the Martian clay detection

The widespread clay minerals on Mars have been detected using orbital data using near-infrared spectroscopy, which is limited by its shallow detection depth, low recognition precision and resolution, and can only be qualitative etc. Terrestrial analogues on the Earth provide valuable guidance to further understand the distribution and occurrence of clay minerals on Mars. In this study, seven detrital samples with clay minerals as coatings (Abbreviated as “clay coatings”) were collected from four sites in the western Qaidam Basin, a Martian analogue terrain. We identify the mineralogy of the surface coatings to be illite and chlorite, as confirmed by a combination techniques of X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Electron Probe X-ray Microanalysis (EPMA) and Near-infrared spectroscopy (NIR). The NIR results suggested that merely small amounts of clay minerals (~0.5 mg/cm2 and about several micrometers in thickness) masking the surface of sands could lead to well-distinguished characteristic NIR absorption, and their band depth could reach those measured from Martian soil analogues with ~5 wt% to 25 wt% clay minerals at 2.20–2.40 μm. The results of the synthesized samples as coating analogues with clay minerals coated on the surface of quartz grains showed a consistent trend as that of the field samples on the Earth. The further mineralogical analysis indicated that the origin of clay minerals in the coatings of Qaidam Basin is of Aeolian source. Environmental similarities between western Qaidam Basin and Martian surface suggested that various rock coatings potentially exist on Mars and they could affect the mineral detection and the accuracy of mineral identification by remote sensing.