Cataluminescence Sensor Research Articles

An ethyl acetate sensor utilizing cataluminescence on Y2O3 nanoparticles

A cataluminescence (CTL) sensor using Y₂O₃ nanoparticles as the sensing materials was proposed for the determination of ethyl acetate. This ethyl acetate sensor showed high sensitivity and specificity at the optimal temperature of 264°C. Quantitative analysis was performed at a wavelength of 425 nm. The linear ranges of CTL intensity vs ethyl acetate concentrations were 2.0-250 ppm (r = 0.9965) and 250-6500 ppm (r = 0.9997) with a detection limit (3σ) of 0.5 ppm. There was no response or weak response when foreign substances such as formic acid, n-hexane, toluene, acetic acid, benzene, and formaldehyde passing through the surface of Y₂O₃ nanoparticles. The sensor had a long lifetime more than 80 h with 3600 ppm ethyl acetate. It had been applied successfully to determine ethyl acetate in artificial air samples.

Graphene sheets decorated with SnO2 nanoparticles: in situ synthesis and highly efficient materials for cataluminescence gas sensors

Graphene sheets decorated with SnO2 nanoparticles were prepared through a facile hydrothermal-assisted in situ synthesis route. According to the XPS, XRD, FESEM and TEM analysis, rutile SnO2 nanocrystals were exclusively deposited on graphene sheets with high density and high uniformity to form layered composite sheets. Propanal, a common volatile organic compound, was selected as a model to investigate the cataluminescence (CTL) sensing properties of the SnO2/graphene composite in this paper. It was found that the strong CTL emission could be generated due to the catalyzing oxidization of propanal on the surface of SnO2/graphene composite and this composite was an efficient sensing material for propanal. We further studied the analytical characteristics of the CTL sensor based on SnO2/graphene composite sensing material for propanal under the optimal experimental conditions. The linear range of the propanal gas sensor was 1.34–266.67 μg mL−1 (r = 0.9987), over two orders of magnitude, and the detection limit was 0.3 μg mL−1(S/N = 3).

A novel cataluminescence gas sensor based on MgO thin film

Using MgO film as sensing material, a cataluminescence sensor was proposed by the determination of ethylene glycol ethers (2-ethoxyethanol and 2-methoxyethanol). This ethylene glycol ethers sensor showed high sensitivity and specificity. With detection limits of 1.0ppm and 1.4ppm, the linear ranges of cataluminescence intensity versus ethylene glycol ethers concentrations were 2.0–2000ppm for 2-ethoxyethanol and 2.0–1500ppm for 2-methoxyethanol, respectively. The response time was less than 5s. Foreign substances passed through the surface of MgO film without response, such as ammonia, benzene, ethyl acetate, acetaldehyde, vinyl acetate, methanol, acetone, ethanol, acetic acid, formaldehyde, and isopropyl ether. The sensor could determine 2-ethoxyethanol and 2-methoxyethanol whether they existed alone or together in air samples.

A new cataluminescence sensor for carbon tetrachloride using its catalytic reduction by hydrogen on palladium/carbon surface

Abstract A new cataluminescence (CTL) sensor was developed based on the chemiluminescence (CL) emission from the catalytic hydrodechlorination of carbon tetrachloride on the surface of palladium/carbon catalyst. The factors influencing the CTL signal, such as the catalyst, carrier gas, gas flow rate, temperature and the CL wavelength, were investigated in detail. Under the optimal conditions, the linear range of the CTL intensity versus concentration of carbon tetrachloride was 4.7–235 μg/mL (R = 0.9944, n = 7), with a limit of detection of 0.7 μg/mL (σ = 3). GC/MS results suggest that the possible CTL mechanism of the reduction is the formation of CCl3 radicals. The CCl3 radicals combine with H free atoms or capture hydrogen atoms from H2 molecules to form excited CHCl3 intermediates, which decay from the excited-state to the ground giving CTL emission for the detection. It is also found that some benzene derivatives with α-H of branched-chain, such as toluene, ethylbenzene and xylenecan, can play a role of catalyst in the reaction.

Development of a sensitive gas sensor by trapping the analytes on nanomaterials and in situ cataluminescence detection

An optical sensor for ethanol has been proposed by trapping the analytes on sensing nanomaterials at room temperature and detecting them in situ by recording the cataluminescence (CTL) signals with fast elevated temperature. Sensing nanomaterials of ZrO2 were directly deposited on heating filament which enables the temperature programming for trapping and detecting the interested analytes. The miniaturized sensing unit has low incandescent radiation so as to provide the high signal-to-noise ratio. Under the optimized conditions, the linear range for the determination of ethanol vapor is 1.0×10−3 to 1.0mgL−1. A detection limit (S/N=3) is 2.0×10−4mgL−1 (0.1ppm), which is improved about 3000-fold for ethanol compared with previous CTL sensors. The relative standard deviation (RSD) is 1.2% (n=7) for ethanol samples at a concentration of 0.08mgL−1. The stability was demonstrated by continuous reaction with ethanol for 120h. This sensor has been applied to monitor the ethanol concentration in human expired gas after drinking, and the results agreed well with the reference values. This miniature ethanol sensor offers higher sensitivity, faster response and lower power consumption, which make it very promising in developing hand-hold sensing device for field detection.

A vinyl acetate sensor based on cataluminescence on MgO nanoparticles

A novel cataluminescence (CTL) sensor using nanosized MgO as the sensing material for determination of the trace of vinyl acetate in air was proposed in the present study. Eight catalysts were examined and the results showed that the CTL intensity on MgO nanoparticles was the strongest. Under the optimized conditions, the linear range of the CTL intensity versus the concentration of vinyl acetate vapor was 2–2000 ppm with a detection limit of 1.0 ppm (3 σ) and a relative standard deviation (R.S.D.) of 1.18% for five times determination of 1000 ppm vinyl acetate. There were no CTL emissions when foreign substances, including ammonia, benzene, acetic acid, formaldehyde and ethyl acetate, passed through the sensor. CTL emissions were detected for methanol, ethanol and acetaldehyde at levels around 5.5%, 10.1% and 13.4% compared with the responsed vinyl acetate. The sensor had a long lifetime more than 100 h.

A novel gaseous dimethylamine sensor utilizing cataluminescence on zirconia nanoparticles

A novel cataluminescence (CTL) sensor using ZrO2 nanoparticles as the sensing material was developed for the determination of trace dimethylamine in air samples based on the catalytic chemiluminescence (CL) of dimethylamine on the surface of ZrO2 nanoparticles. The CTL characteristics and the different factors on the signal intensity for the sensor, including nanomaterials, working temperature, wavelength and airflow rate, were investigated in detail. The CL intensity on ZrO2 nanoparticles was the strongest among the seven examined catalysts. This novel CL sensor showed high sensitivity and selectivity to gaseous dimethylamine at optimal temperature of 330 degrees C. Quantitative analysis was performed at a wavelength of 620 nm. The linear range of CTL intensity vs concentration of gaseous dimethylamine was 4.71 x 10(-3) to 7.07 x 10(-2 )mg L(-1) (r = 0.9928) with a detection limit (3sigma) of 6.47 x 10(-4) mg L(-1). No or only very low levels of interference were observed while the foreign substances such as benzene, hydrochloric acid, methylbenzene, chloroform, n-hexane and water vapor were passing through the sensor. The response time of the sensor was less than 50 s, and the sensor had a long lifetime of more than 60 h. The sensor was successfully applied to the determination of dimethylamine in artificial air samples, and could potentially be applied to analysis of nerve agents such as Tabun (GA).

A novel gaseous pinacolyl alcohol sensor utilizing cataluminescence on alumina nanowires prepared by supercritical fluid drying

A cataluminescence (CTL) sensor using Al 2O 3 nanowires as the sensing material was developed for the determination of trace pinacolyl alcohol in air samples based on the catalytic chemiluminescence (CL) of pinacolyl alcohol on Al 2O 3 nanowires. Eight catalysts were examined and the CL intensity on Al 2O 3 nanowires prepared by supercritical fluid drying was the strongest. This novel CL sensor showed high sensitivity and selectivity to gaseous pinacolyl alcohol at optimal temperature of 340 °C. Quantitative analysis was performed at a wavelength of 460 nm. The linear range of CTL intensity versus concentration of gaseous pinacolyl alcohol was 0.09 × 10 −6 to 2.56 × 10 −6 g mL −1 ( r = 0.9983, n = 6) with a detection limit (3 σ) of 0.0053 × 10 −6 g mL −1. None or only very low levels of interference were observed while the foreign substances such as water vapor, ethanol, ammonia, chloroform, benzene, nitrogen dioxide, methylbenzene, hydrochloric acid, methanol and butanol were passing through the sensor. The response time of the sensor is less than 100 s, and the sensor had a long lifetime more than 60 h. The sensor would be potentially applied to analysis of the nerve agents such as Soman.

Direct Solid-Support Sample Loading for Fast Cataluminescence Determination of Acetone in Human Plasma

In the current manuscript we describe the development of a novel cataluminescence (CTL) sensor coupled with ionic liquids (ILs)-based headspace solid-phase microextraction (HS-SPME) technologies for the quantification of human plasma acetone levels associated with diabetic disease ex vivo. The unique properties of ILs, such as their nonvolatile and nonflammable nature, coupled with their high thermal stability allow ILs to be conveniently adopted as pseudosolid carriers for direct loading of acetone into a CTL sensor without matrix interference. Acetone from diabetic patient plasma and plasma samples spiked with acetone along with methanol, ethanol, and formaldehyde was conveniently and rapidly extracted and enriched in 3 microL of IL and then rapidly quantified by our CTL sensor. The presence of plasma alone or spiked plasma containing methanol, ethanol, or formaldehyde did not interfere with acetone measurements. HS-SPME-CTL provides higher enrichment efficiency than headspace single-drop microextraction-based CTL (HS-SDME-CTL) methods, possibly due to that the thin film formed in HS-SPME instead of the single IL drop in HS-SDME increases the exchange area for extracted acetone. The enrichment efficiency by HS-SPME-CTL was almost 80-fold higher than that with direct injection using the same volume of aqueous samples and more than 6-fold higher than that using HS-SDME-CTL. Considering that ILs can be easily prepared from inexpensive materials and tuned by the combination of different anions and cations for the extraction of specific analytes from various solvent media, this proposed technology raises an exciting possibility by employing HS-SPME-CTL for the fast determination of specific targets in many fields.

Zeolite‐based cataluminescence sensor for the selective detection of acetaldehyde

The reactions of acetaldehyde with O atoms in the cages of large-pore zeolites have been discovered to result in light emission. The luminescence characteristics of acetaldehyde vapours passing through the surface of chosen zeolites were studied using a cataluminescence-based detection system. To demonstrate the feasibility of the method, the detection of acetaldehyde using catalysts was studied systematically and a linear response of 0.06-31.2 microg/mL acetaldehyde vapour was obtained. Methanol, ethanol, isopropanol, methylbenzene, chloroform, dichlormethane and acetonitrile did not interfere with the determination of acetaldehyde. Acetaldehyde vapour could also be distinguished from some homologous series such as formaldehyde, cinnamaldehyde, glutaraldehyde and benzaldehyde on this catalyst, possibly due to the stereoselectivity of the zeolite and its specific reaction mechanism. Moreover, acetaldehyde was quantified without detectable interference from formaldehyde in four artificial samples. Thus, this kind of cataluminescence-based sensor could be potentially extended to the analysis of volatile organic compounds in air, and the simple and portable properties of cataluminescence-based sensors could also make them beneficial in many areas of analytical science.

Cataluminescence and catalytic reactions of ethanol oxidation over nanosized Ce 1− xZr xO 2 (0 ⩽ x ⩽ 1) catalysts

Cataluminescence (CTL) and catalytic reactions of ethanol oxidation over nanosized (5–20 nm) Ce 1− x Zr x O 2 (0 ⩽ x ⩽ 1) materials were studied at 170–300 °C. Characterization with XRD showed that the Ce 1− x Zr x O 2 material was a CeO 2-based solid solution in the cubic phase at x ⩽ 0.15; it became a phase mixture of the solid solution and tetragonal ZrO 2 at 0.15 < x < 1. The materials that were rich in the solid solution phase (i.e., x = 0.05–0.25) showed very high CTL activity at 220 °C and thus can be considered as efficient low-temperature CTL sensors for ethanol. The CTL intensity of ethanol oxidation was closely related to the steady state activity of the Ce 1− x Zr x O 2 catalysts for oxidative dehydrogenation of ethanol to form acetaldehyde.

A research on determination of explosive gases utilizing cataluminescence sensor array

In this paper, we propose a model of a sensor array system, which consists of three cataluminescence sensors based on nanosized SrCO3, gamma-Al2O3 and BaCO3 as catalysts, for quantitative analysis of the explosive gases of propane, n-butane and iso-butane in a mixture. Six linear regression equations of the cataluminescence intensity vs. the gas concentrations in the range 2000-10,000 ppm were established from the sensor array system at two working temperatures, as the explosive gases show different sensitivity to the three sensors. The least squares method was employed for solving the simultaneous equations and quantifying the concentrations of the three components. The detection limits (3sigma) of propane, n-butane and iso-butane on SrCO3, gamma-Al2O3 and BaCO3 sensors are 50, 40 and 20 ppm, 80, 60 and 40 ppm, and 20, 10 and 5 ppm, respectively. The concentrations of two artificial samples containing the tertiary mixture were analysed with satisfactory results.

An energy-transfer cataluminescence reaction on nanosized catalysts and its application to chemical sensors

When reductive gases pass over the surface of nanosized catalysts, a kind of chemiluminescence named cataluminescence (CTL) can be generated due to the production of excited intermediates. Here we report the observation of an energy transfer process between excited intermediates and the nanosized catalysts. The CTL is quenched when introducing Ho 3+, Co 2+ and Cu 2+ into the catalyst, while new intensive CTL peaks appear when the catalyst is doped with Eu 3+ or Tb 3+. Further study indicates that the new CTL peak on Eu 3+- or Tb 3+-doped catalyst originates from the luminescence of the doped ions, excited by the energy transferred from excited intermediates produced during the reaction. Based on this novel energy-transfer CTL (ETCTL), an ethanol sensor is developed with Eu 3+-doped nanosized ZrO 2 that is linear to ethanol concentrations from 45 to 550 ppm, with the whole linear range lower than the lower limit of the previous CTL sensor. The ETCTL from Eu 3+-doped in nanosized ZrO 2 shows 72 times higher sensitivity than the CTL from excited intermediates in the sensor. High selectivity and stability are also obtained for this sensor. The results also indicate that the main factor limiting the sensitivity of CTL sensor on pure catalyst may be the inevitable energy quenching of excited intermediates with the catalyst, which is artfully utilized in the present work by the introduction of Eu 3+ that effectively absorbs this part of energy and transfers it into light energy.

A novel gaseous acetaldehyde sensor utilizing cataluminescence on nanosized BaCO 3

A cataluminescence (CTL) sensor using nanosized BaCO 3 as sensing material for the determination of trace acetaldehyde in air samples was developed. The proposed sensor showed high sensitivity and selectivity to acetaldehyde at optimal temperature of 225 °C. Quantitative analysis was performed at a wavelength of 555 nm. The linear range of CTL intensity versus concentration of acetaldehyde is 2–2000 ppm ( r=0.9981, n=8), with a detection limit of 0.5 ppm (signal-to-noise ratio = 3). None or only very low levels of significant interference were observed while the foreign substances such as cyclohexane, n-hexane, carbon tetrachloride, ammonia, methylbenzene, chloroform, benzene, formaldehyde, ethanol and carbon dioxide are passing through the sensor. There was no interference due to the 20 000 ppm water vapor in the determination of 200 ppm acetaldehyde vapor. The stability of the sensor was tested by continuous reaction with acetaldehyde for 100 h. The response time of the sensor is less than 50 s.