Parental perspectives and concerns regarding exotropia surgery and comparison with clinicians' predictions.

PURPOSE: To evaluate parental perspectives and concerns regarding exotropia surgery and compare them with clinicians' predictions of parental responses in Korean pediatric patients with intermittent exotropia. METHODS: This survey study included the parents of pediatric patients with intermittent exotropia who underwent surgery and clinicians at five hospitals from June 2022 to February 2023, who participated in the Survey of Parental Attitude and Concerns of Exotropia surgery (SPACE) study 1. Parental attitudes and concern about exotropia surgery were assessed using a questionnaire. Clinicians' estimation of each item corresponding to the parental questionnaire was also assessed and compared with parental responses. RESULTS: A total of 266 parents and 41 clinicians were included. More parents responded that information about surgery was most helpful or most commonly received from clinicians than clinicians estimated (P = 0.001). More parents reported actively communicating with the child about surgery than clinicians estimated (P < 0.001). Parents showed a higher level of concern for general anesthesia and the hospital environment than clinicians thought they would (P = 0.002 and P < 0.001, resp.). In the postoperative follow-up items, parents showed high levels of concern regarding postoperative infection (P < 0.001), conjunctival redness (P = 0.040), persistent overcorrection (P < 0.001), and glasses wearing (P = 0.019). CONCLUSIONS: Parental perspectives and concerns regarding pediatric intermittent exotropia surgery differed from clinicians' estimations thereof. More parents obtain information on exotropia surgery from clinicians and actively talk about surgery with their child than estimated by clinicians. Parents had a higher level of concern regarding general anesthesia, hospital environment, postoperative infection, conjunctival redness, persistent overcorrection, and glasses wearing compared with clinician estimations.

Zinc-copper dual-ion electrolytes to suppress dendritic growth and increase anode utilization in zinc ion capacitors.

The main bottlenecks that hinder the performance of rechargeable zinc electrochemical cells are their limited cycle lifetime and energy density. To overcome these limitations, this work studied the mechanism of a dual-ion Zn-Cu electrolyte to suppress dendritic formation and extend the device cycle life while concurrently enhancing the utilization ratio of zinc and thereby increasing the energy density of zinc ion capacitors (ZICs). The ZICs achieved a best-in-class energy density of 41 watt hour per kilogram with a negative-to-positive (n/p) electrode capacity ratio of 3.10. At the n/p ratio of 5.93, the device showed a remarkable cycle life of 22,000 full charge-discharge cycles, which was equivalent to 557 hours of discharge. The cumulative capacity reached ~581 ampere hour per gram, surpassing the benchmarks of lithium and sodium ion capacitors and highlighting the promise of the dual-ion electrolyte for delivering high-performance, low-maintenance electrochemical energy supplies.

Exclusive detection of volatile aromatic hydrocarbons using bilayer oxide chemiresistors with catalytic overlayers.

The accurate detection and identification of volatile aromatic hydrocarbons, which are highly toxic pollutants, are essential for assessing indoor and outdoor air qualities and protecting humans from their sources. However, real-time and on-site monitoring of aromatic hydrocarbons has been limited by insufficient sensor selectivity. Addressing the issue, bilayer oxide chemiresistors are developed using Rh-SnO2 gas-sensing films and catalytic CeO2 overlayers for rapidly and cost-effectively detecting traces of aromatic hydrocarbons in a highly discriminative and quantitative manner, even in gas mixtures. The sensing mechanism underlying the exceptional performance of bilayer sensor is systematically elucidated in relation to oxidative filtering of interferants by the CeO2 overlayer. Moreover, CeO2-induced selective detection is validated using SnO2, Pt-SnO2, Au-SnO2, In2O3, Rh-In2O3, Au-In2O3, WO3, and ZnO sensors. Furthermore, sensor arrays are employed to enable pattern recognition capable of discriminating between aromatic gases and non-aromatic interferants and quantifying volatile aromatic hydrocarbon classifications.

Risk factors for early-onset exfoliation syndrome.

Although exfoliation syndrome (XFS) is an age-related, late-onset disease, early-onset XFS has been reported, and its associated factors remain unknown. In this study, we investigated the clinical features and risk factors of early-onset XFS. The participants were divided into two groups according to age at the time of XFS diagnosis: early-onset (< 60 years) or late-onset (≥ 70 years) group. Among the 302 eyes of 240 patients with XFS, the early-onset group included 41 eyes (14%) of 33 patients, and the late-onset group included 163 eyes (54%) of 126 patients; the mean age was 54.8 ± 5.0 and 76.6 ± 4.9 years, respectively (p < 0.001). All eight cases diagnosed with XFS at the earliest age, ranging from 36 to 52 years, underwent trabeculectomy before the diagnosis of XFS. Multivariable logistic regression analysis showed that a history of trabeculectomy (odds ratio [OR] = 11.435, p < 0.001), presence of iridectomy (OR = 11.113, p < 0.001), and longer axial length (OR = 2.311, p = 0.003) were significantly associated with the development of early-onset XFS. Collectively, patients with early-onset XFS were more likely to have undergone trabeculectomy and have more axial myopia compared with those with late-onset XFS. These findings suggest that surgical trauma compromising the blood-aqueous barrier may trigger early manifestation of XFS.

Designing oxide chemiresistors for detecting volatile aromatic compounds: recent progresses and future perspectives.

Oxide chemiresistors have mostly been used to detect reactive gases such as ethanol, acetone, formaldehyde, nitric dioxide, and carbon monoxide. However, the selective and sensitive detection of volatile aromatic compounds such as benzene, toluene, and xylene, which are extremely toxic and harmful, using oxide chemiresistors remains challenging because of the molecular stability of benzene rings containing chemicals. Moreover, the performance of the sensing materials is insufficient to detect trace concentration levels of volatile aromatic compounds, which lead to harmful effects on human beings. Here, the strategies for designing highly selective and sensitive volatile aromatic compound gas sensors using oxide chemiresistors were suggested and reviewed. Key approaches include the use of thermal activation, design of sensing materials with high catalytic activity, the utilization of catalytic microreactors and bilayer structures with catalytic overlayer, and the pretreatment of analyte gases or post analysis of sensing signals. In addition, future perspectives from the viewpoint of designing sensing materials and sensor structures for high-performance and robust volatile aromatic compounds gas sensors are provided. Finally, we discuss possible applications of the sensors and sensor arrays.

Highly Selective and Sensitive Detection of Breath Isoprene by Tailored Gas Reforming: A Synergistic Combination of Macroporous WO3 Spheres and Au Catalysts.

Precise detection of breath isoprene can provide valuable information for monitoring the physical and physiological status of human beings or for the early diagnosis of cardiovascular diseases. However, the extremely low concentration and low chemical reactivity of breath isoprene hamper the selective and sensitive detection of isoprene using oxide semiconductor chemiresistors. Herein, we report that macroporous WO3 microspheres whose inner macropores are surrounded by Au nanoparticles exhibit a high response (resistance ratio = 11.3) to 0.1 ppm isoprene under highly humid conditions at 275 °C and an extremely low detection limit (0.2 ppb). Furthermore, the sensor showed excellent selectivity to isoprene over five interferants that could be exhaled by humans. Notably, the selectivity to isoprene is critically dependent on the location of Au nanocatalysts and macroporosity. The mechanism underlying the selective isoprene detection is investigated in relation to the reforming of less reactive isoprene into more reactive intermediate species promoted by macroporous catalytic reactors, which is confirmed by the analysis using a proton transfer reaction quadrupole mass spectrometer. The sensor for breath analysis has high potential for simple physical and physiological monitoring as well as disease diagnosis.

Choroidal vascular alterations evaluated by ultra-widefield indocyanine green angiography in central serous chorioretinopathy.

PURPOSE: This study aims to evaluate choroidal vascular alterations in patients with central serous chorioretinopathy (CSC) using ultra-widefield (UWF) indocyanine green angiography (ICGA). METHODS: This was a retrospective case-control study conducted at a single tertiary eye center. In total, 36 eyes in patients with either unilateral (24 patients) or bilateral (six patients) treatment-naïve CSC and 30 eyes in 24 age-matched controls were evaluated. The number of quadrants with vortex vein engorgement on UWF ICGA was evaluated. Dilated choroidal vessels affecting the macula were regarded as extended vortex vein engorgement. Choroidal vascular hyperpermeability (CVH) area on late-phase ICGA was quantified using stereographic projection. The parameters were compared with clinical and optical coherence tomographic findings. RESULTS: Eyes with CSC had larger CVH area, thicker choroid, and more quadrants with vortex vein engorgement and extended vortex vein engorgement compared with control eyes (all P < 0.001). In patients with unilateral CSC, affected eyes had larger CVH area, thicker choroid, and more extended vortex vein engorgements compared with unaffected fellow eyes (all P < 0.001), but vortex vein engorgement did not significantly differ. CVH was significantly correlated with extended vortex vein engorgement (P < 0.001) and subfoveal choroidal thickness (P = 0.007). CONCLUSIONS: The increased number and binocular symmetry of engorged vortex veins suggest an anatomical predisposition for CSC. CVH area and extended vortex vein engorgement were indicators of choroidal outflow congestion. These parameters may serve as diagnostic clues or predictors of disease development in eyes with CSC.

Exclusive and ultrasensitive detection of formaldehyde at room temperature using a flexible and monolithic chemiresistive sensor.

Formaldehyde, a probable carcinogen, is a ubiquitous indoor pollutant, but its highly selective detection has been a long-standing challenge. Herein, a chemiresistive sensor that can detect ppb-level formaldehyde in an exclusive manner at room temperature is designed. The TiO2 sensor exhibits under UV illumination highly selective detection of formaldehyde and ethanol with negligible cross-responses to other indoor pollutants. The coating of a mixed matrix membrane (MMM) composed of zeolitic imidazole framework (ZIF-7) nanoparticles and polymers on TiO2 sensing films removed ethanol interference completely by molecular sieving, enabling an ultrahigh selectivity (response ratio > 50) and response (resistance ratio > 1,100) to 5 ppm formaldehyde at room temperature. Furthermore, a monolithic and flexible sensor is fabricated successfully using a TiO2 film sandwiched between a flexible polyethylene terephthalate substrate and MMM overlayer. Our work provides a strategy to achieve exclusive selectivity and high response to formaldehyde, demonstrating the promising potential of flexible gas sensors for indoor air monitoring.

Effects of refractive power on quantification using ultra-widefield retinal imaging.

BACKGROUND: Ultra-widefiled (UWF) retinal images include significant distortion when they are projected onto a two-dimensional surface for viewing. Therefore, many clinical studies that require quantitative analysis of fundus images have used stereographic projection algorithm, three-dimensional fundus image was mapped to a two-dimensional stereographic plane by projecting all relevant pixels onto a plane through the equator of the eye. However, even with this impressive algorithm, refractive error itself might affect the size and quality of images theoretically. The purpose of this study is to investigate the effects of refractive power on retinal area measurements (quantification) using UWF retinal imaging (Optos California; Dunfermline, Scotland, UK). METHODS: A prospective, interventional study comprised 50 healthy eyes. UWF images were acquired first without the use of a soft contact lens (CL) and then repeated with six CLs (+ 9D, +6D, +3D, -3D, -6D, and - 9D). Using stereographically projected UWF images, the optic disc was outlined by 15-17 points and quantified in metric units. We divided the subjects into three groups according to axial length: Groups A (22-24 mm), B (24-26 mm), and C (≥ 26 mm). The primary outcome was percentage change before and after use of the CLs. Secondary outcome was proportion of subjects with magnification effects, maximal changes > 10 %. RESULTS: The study population was 6, 28, and 16 eyes in each group. Overall changes for the measured area were not significantly different in the whole study population. Group C had a larger proportion of magnification effects compared to Groups A and B (50.0 %, 0 %, and 3.6 %, P = 0.020). Measured area with plus lenses was significantly higher in Group C (P < 0.001). CONCLUSIONS: The use of CLs might affect quantification of eyes with long axial length when using UWF images. Ophthalmologists should consider refractive error when measuring area in long eyes.

Highly Selective Detection of Benzene and Discrimination of Volatile Aromatic Compounds Using Oxide Chemiresistors with Tunable Rh-TiO2 Catalytic Overlayers.

Volatile aromatic compounds are major air pollutants, and their health impacts should be assessed accurately based on the concentration and composition of gas mixtures. Herein, novel bilayer sensors consisting of a SnO2 sensing layer and three different xRh-TiO2 catalytic overlayers (x = 0.5, 1, and 2 wt%) are designed for the new functionalities such as the selective detection, discrimination, and analysis of benzene, toluene, and p-xylene. The 2Rh-TiO2/SnO2 bilayer sensor shows a high selectivity and response toward ppm- and sub-ppm-levels of benzene over a wide range of sensing temperatures (325-425 °C). An array of 0.5Rh-, 1Rh-, and 2Rh-TiO2/SnO2 sensors exhibits discrimination and composition analyses of aromatic compounds. The conversion of gases into more active species at moderate catalytic activation and the complete oxidation of gases into non-reactive forms by excessive catalytic promotion are proposed as the reasons behind the enhancement and suppression of analyte gases, respectively. Analysis using proton transfer reaction-quadrupole mass spectrometer (PTR-QMS) is performed to verify the above proposals. Although the sensing characteristics exhibit mild moisture interference, bilayer sensors with systematic and tailored control of gas selectivity and response provide new pathways for monitoring aromatic air pollutants and evaluating their health impacts.

Optimal fluence rate of photodynamic therapy for chronic central serous chorioretinopathy.

AIMS: To investigate the lowest effective fluence rate of photodynamic therapy (PDT) for treating chronic central serous chorioretinopathy (CSC). METHODS: Fifty-one eyes of 51 patients with chronic CSC were randomly treated with 30% (n=15), 40% (n=16) or 50% (n=17) of the standard-fluence rate of PDT and followed up for 12 months. The success rate, recurrence rate, mean best-corrected visual acuity (BCVA), central foveal thickness (CFT), subfoveal choroidal thickness (SFCT), integrity of the outer retinal layer and complications were evaluated at baseline and at the follow-up periods after PDT. RESULTS: The rate of complete subretinal fluid (SRF) resolution in the 30%-fluence, 40%-fluence and 50%-fluence groups was 60.0%, 81.2% and 100.0%, respectively, at 3 months (p=0.009), and 80.0%, 94.0% and 100.0%, respectively, at 12 months (p=0.06). The recurrence rate in the 50%-fluence group was lower than that in the 30%- and 40%-fluence groups at 12 months (30% vs 50%, 40% vs 50%; p=0.002, p=0.030, respectively (log-rank test)). The mean BCVA improved significantly 12 months after PDT only in the 40%- and 50%-fluence groups (p=0.005, p=0.003, respectively). Mean CFT and SFCT decreased significantly at 12 months in the three groups. The rate of complications did not differ significantly among the three groups. CONCLUSIONS: A 50%-fluence rate of PDT seems to be the most effective for treating chronic CSC, considering the low recurrence rate and high rate of complete SRF resolution, compared with other low-fluence PDT. TRIAL REGISTRATION NUMBER: NCT01630863.

General Strategy for Designing Highly Selective Gas-Sensing Nanoreactors: Morphological Control of SnO2 Hollow Spheres and Configurational Tuning of Au Catalysts.

Catalyst-loaded hollow spheres are effective at detecting ethanol with high chemical reactivity. However, this has limited the widespread use of catalyst-loaded hollow spheres in designing highly selective gas sensors to less-reactive gases such as aromatics (e.g., xylene). Herein, we report the preparation of xylene-selective Au-SnO2 nanoreactors by loading Au nanoclusters on the inner surface of SnO2 hollow shells using the layer-by-layer assembly technique. The results revealed that the sensor based on SnO2 hollow spheres loaded with Au nanoclusters on the inner surface exhibited unprecedentedly high xylene selectivity and an ultrahigh xylene response, high enough to be used for indoor air quality monitoring, whereas the sensor based on SnO2 hollow spheres loaded with Au nanoclusters on the outer surface exhibited the typical ethanol-sensitive sensing behaviors as frequently reported in the literature. In addition, the xylene selectivity and response were optimized when the hollow shell was sufficiently thin (∼25 nm) and semipermeable (pore size = ∼3.5 nm), while the selectivity and response decreased when the shell was thick or highly gas permeable with large mesopores (∼30 nm). Accordingly, the underlying mechanism responsible for the unprecedentedly high xylene sensing performance is discussed in relation to the configuration of the loaded Au nanoclusters and the morphological characteristics including shell thickness and pore size distribution. This novel nanoreactor concept can be widely used to design highly selective gas sensors especially to less-reactive gases such as aromatics, aldehydes, and ketones.

Delayed-Onset Retrobulbar Hemorrhage and Glaucoma Drainage Device Extrusion in a Patient on Anticoagulation: A Case Report.

Both retrobulbar hemorrhage and plate extrusion are uncommon complications after implantation of a glaucoma drainage device (GDD). There are no published reports on extrusion of an Ahmed glaucoma valve after delayed-onset retrobulbar hemorrhage in Korea. Herein, we report a case of spontaneous extrusion of a GDD after delayed-onset retrobulbar hemorrhage in a patient on anticoagulation. The case was a 72-year-old man with open-angle glaucoma and proliferative diabetic retinopathy, as well as systemic hypertension, atrial fibrillation, congestive heart failure due to coronary heart disease, and chronic kidney disease, who underwent combined Ahmed glaucoma valve implantation and cataract extraction surgery in his right eye. The body remained in position with control of intraocular pressure for 2 months. On day 67 (5 days post-coronary artery bypass surgery), he complained of decreased visual acuity, periorbital swelling, bloody discharge, and limited extraocular movement. One month later, the body was extruded with a scleral flap tear. Therefore, delayed-onset retrobulbar hemorrhage should be kept in mind in patients on anticoagulants after insertion of a GDD.

Management of a Submacular Hemorrhage Secondary to Age-Related Macular Degeneration: A Comparison of Three Treatment Modalities.

This paper aims to compare the effects of three treatment modalities for a submacular hemorrhage (SMH) secondary to exudative age-related macular degeneration (AMD). Seventy-seven patients with an SMH were divided into three groups: small-sized (optic disc diameter (ODD) ≥ 1 to < 4), medium-sized (ODD ≥ 4 within the temporal arcade) and large-sized (ODD ≥ 4, exceeding the temporal arcade). Patients received anti-vascular endothelial growth factor (anti-VEGF) monotherapy, pneumatic displacement (PD) with anti-VEGF or a vitrectomy with a subretinal tissue plasminogen activator (tPA) and gas tamponade based on the surgeon's discretion. The functional and anatomical outcomes were evaluated. Among the 77 eyes, 45 eyes had a small-sized, 21 eyes had a medium-sized and 11 eyes had a large-sized SMH. In the small-sized group, all treatment modalities showed a gradual best-corrected visual acuity (BCVA) improvement with high hemorrhagic regression or displacement rates (over 75%). In the medium-sized group, PD and surgery were associated with better BCVA with more displacement than anti-VEGF monotherapy (67% and 83%, respectively, vs. 33%). In the large-sized group, surgery showed a better visual improvement with a higher displacement rate than PD (86% vs. 25%). Our findings demonstrated that visual improvement can be expected through appropriate treatment strategy regardless of the SMH size. In cases with a larger SMH, invasive techniques including PD or surgery were more advantageous than anti-VEGF monotherapy.

Rational Design of Semiconductor-Based Chemiresistors and their Libraries for Next-Generation Artificial Olfaction.

Artificial olfaction based on gas sensor arrays aims to substitute for, support, and surpass human olfaction. Like mammalian olfaction, a larger number of sensors and more signal processing are crucial for strengthening artificial olfaction. Due to rapid progress in computing capabilities and machine-learning algorithms, on-demand high-performance artificial olfaction that can eclipse human olfaction becomes inevitable once diverse and versatile gas sensing materials are provided. Here, rational strategies to design a myriad of different semiconductor-based chemiresistors and to grow gas sensing libraries enough to identify a wide range of odors and gases are reviewed, discussed, and suggested. Key approaches include the use of p-type oxide semiconductors, multinary perovskite and spinel oxides, carbon-based materials, metal chalcogenides, their heterostructures, as well as heterocomposites as distinctive sensing materials, the utilization of bilayer sensor design, the design of robust sensing materials, and the high-throughput screening of sensing materials. In addition, the state-of-the-art and key issues in the implementation of electronic noses are discussed. Finally, a perspective on chemiresistive sensing materials for next-generation artificial olfaction is provided.

A New Strategy for Detecting Plant Hormone Ethylene Using Oxide Semiconductor Chemiresistors: Exceptional Gas Selectivity and Response Tailored by Nanoscale Cr2O3 Catalytic Overlayer.

A highly selective and sensitive detection of the plant hormone ethylene, particularly at low concentrations, is essential for controlling the growth, development, and senescence of plants, as well as for ripening of fruits. However, this remains challenging because of the non-polarity and low reactivity of ethylene. Herein, a strategy for detecting ethylene at a sub-ppm-level is proposed by using oxide semiconductor chemiresistors with a nanoscale oxide catalytic overlayer. The SnO2 sensor coated with the nanoscale catalytic Cr2O3 overlayer exhibits rapid sensing kinetics, good stability, and an unprecedentedly high ethylene selectivity with exceptional gas response (R a/R g - 1, where R a represents the resistance in air and R g represents the resistance in gas) of 16.8 at an ethylene concentration of 2.5 ppm at 350 °C. The sensing mechanism underlying the ultraselective and highly sensitive ethylene detection in the unique bilayer sensor is systematically investigated with regard to the location, configuration, and thickness of the catalytic Cr2O3 overlayer. The mechanism involves the effective catalytic oxidation of interfering gases into less- or non-reactive species, without limiting the analyte gas transport. The sensor exhibits a promising potential for achieving a precise quantitative assessment of the ripening of five different fruits.

Metal Oxide Gas Sensors with Au Nanocluster Catalytic Overlayer: Toward Tuning Gas Selectivity and Response Using a Novel Bilayer Sensor Design.

Noble metals or oxide catalysts have traditionally been loaded or doped to enhance the gas sensing properties of oxide semiconductor chemiresistors. However, the selective detection of various chemicals for a wide range of new applications remains a challenging problem. In this paper, we propose a novel bilayer design with an oxide chemiresistor sensing layer and nanoscale catalytic Au overlayer to provide high controllability for gas sensing characteristics. The Au nanocluster overlayer significantly enhances the methylbenzene response of a SnO2 thick film sensor by reforming gases into more reactive species and suppresses the responses to reactive interference gases through oxidative filtering, leading to excellent selectivity to methylbenzene. Gas sensing characteristics can be tuned by controlling the morphology, amount, and number density of Au nanoclusters through the variation in the Au coating thickness (0.5-3 nm) and thermal annealing conditions (0.5-4 h at 550 °C). Furthermore, the general validity of the proposed Au-coated bilayer sensor design was confirmed through the enhancement of response and selectivity toward methylbenzenes by coating Au nanoclusters onto ZnO and Co3O4 sensors. The sensing mechanism, advantages, and potential applications of bilayer sensors are discussed from the perspective of the separation of sensing and catalytic reactions, as well as the reforming and oxidation of analyte gases in association with the configuration of the sensing layer and Au catalytic overlayer.

Humidity-Independent Gas Sensors Using Pr-Doped In2O3 Macroporous Spheres: Role of Cyclic Pr3+/Pr4+ Redox Reactions in Suppression of Water-Poisoning Effect.

Pure and 3-12 at. % Pr-doped In2O3 macroporous spheres were fabricated by ultrasonic spray pyrolysis and their acetone-sensing characteristics under dry and humid conditions were investigated to design humidity-independent gas sensors. The 12 at. % Pr-doped In2O3 sensor exhibited approximately the same acetone responses and sensor resistances at 450 °C regardless of the humidity variation, whereas the pure In2O3 exhibited significant deterioration in gas-sensing characteristics upon the change in the atmosphere, from dry to humid (relative humidity: 80%). Moreover, the 12 at. % Pr-doped In2O3 sensor exhibited a high response to acetone with negligible cross responses to interfering gases (NH3, CO, benzene, toluene, NO2, and H2) under the highly humid atmosphere. The mechanism for the humidity-immune gas-sensing characteristics was investigated by X-ray photoelectron and diffuse reflectance infrared Fourier transform spectroscopies together with the phenomenological gas-sensing results and discussed in relation with Pr3+/Pr4+ redox pairs, regenerative oxygen adsorption, and scavenging of hydroxyl groups.

Highly Sensitive and Selective PbTiO3 Gas Sensors with Negligible Humidity Interference in Ambient Atmosphere.

Three PbTiO3 nanostructures were synthesized using a one-step hydrothermal reaction with different TiO2 powders as Ti sources, and their gas-sensing properties were investigated. The sensor comprising PbTiO3 nanoplates (NPs) exhibited a high response (resistance ratio = 80.4) to 5 ppm ethanol at 300 °C and could detect trace concentrations of ethanol down to 100 ppb. Moreover, the sensor showed high ethanol selectivity and nearly the same sensing characteristics despite the wide range of humidity variation from 20 to 80% RH. The mechanism for humidity-independent gas sensing was elucidated using diffuse reflectance infrared Fourier transform spectra. PbTiO3 NPs are new and promising sensing materials that can be used for detecting ethanol in a highly sensitive and selective manner with negligible interference from ambient humidity.