Detection Of CO Research Articles

Tailoring CO2 detection capabilities using Co-ZnO/MoS2 nanocomposites through electrolyte concentration modulation

AbstractThe current study explores a new approach to investigate the CO2 detection capabilities of cobalt-doped zinc oxide (Co-ZnO) combined with molybdenum sulfide (MoS2) hybrid nanomaterials Co-ZnO/MoS2 (CZM). The hydrothermally synthesized CZM composites provide unique structural and compositional properties, with 25 nm as their longest dimension (length), and specific lattice structure. CZM-based electrodes are developed by preparing the nanomaterial-dispersed ink, and potentiometric studies explore the optimal sensing performance. We found significant enhancements in sensitivity, reaction time, and reduction efficiency by systematically changing the electrolyte concentration in the electrode cell. Bode and Nyquist plots explain the influence of electrolyte concentration and the nanomaterial synergy in CO2 sensing and conversion with the 0.1 N electrolyte with the maximum efficiency. By offering important insights into how the electrolyte content affects the performance of Co-ZnO/MoS2 nanocomposite sensors, this study advances the field of CO2 sensing technology. Further, the nanomaterials extend their applicability in environmental monitoring, evaluating indoor air quality, and industrial processes.

The tight correlation between PAH and CO emission from z ∼ 0 to 4

Aims. The cold molecular gas mass is one of the crucial, yet challenging, parameters in galaxy evolution studies. Here, we introduce a new calibration and a method for estimating molecular gas masses using mid-infrared (MIR) photometry. This topic is timely as the James Webb Space Telescope (JWST) now allows us to detect the MIR emission of typical main-sequence galaxies across a wide range of masses and star formation rates with modest time investments. Additionally, this Letter highlights the strong synergy between ALMA and JWST for studies of dust and gas at cosmic noon. Methods. We combined a sample of 14 main-sequence galaxies at z = 1 − 3 with robust CO detections and multi-band MIR photometry, along with a literature sample at z = 0 − 4 with CO and polycyclic aromatic hydrocarbon (PAH) spectroscopy, to study the relationship between PAH, CO(1–0), and total IR luminosities. PAH luminosities are derived by modelling a wealth of rest-frame UV to sub-millimetre data. The new z = 1 − 3 sample extends previous high-z studies to PAH and CO luminosities that are about an order of magnitude lower, into the regime of local starbursts, for the first time. Results. The PAH-to-CO luminosity ratio remains constant across a wide range of luminosities, for various galaxy types, and throughout the explored redshift range. In contrast, the PAH-to-IR and CO-to-IR luminosity ratios deviate from a constant value at high IR luminosities. The intrinsic scatter in the L(PAH)–L′(CO) relation is 0.21 dex, with a median of 1.40 and a power-law slope of 1.07 ± 0.04. Both the PAH–IR and CO–IR relations are sub-linear. Given the tight and uniform PAH–CO relation over ∼3 orders of magnitude, we provide a recipe for estimating the cold molecular gas mass of galaxies from PAH luminosities, with a PAH-to-molecular gas conversion factor of αPAH7.7 = (3.08 ± 1.08)(4.3/αCO) M⊙/L⊙. This method opens a new window to explore the gas content of galaxies beyond the local Universe using multi-wavelength JWST/MIRI imaging.

Silica/carbon dot nanosorbent for the detection and removal of Pb(II) and Co(II) ions from wastewater

In excess, cobalt and lead ions adversely affect both the environment and ecosystems, having negative impact on agricultural plants and feed cultures as well as fish, animal, and human health. In this study, a three-component sorbent based on carbon dots (CDs), hydroxypropyl methyl cellulose (HPMC), and silica (SiO2) was developed for the removal of cobalt(II) and lead(II) ions from aqueous media. CDs synthesized directly on the HPMC surface were condensed with SiO2 via the hydrolysis of tetraethyl siloxane. As a result, a recyclable porous CD/HPMC/SiO2 nanosorbent with high sorption capacity was synthesized. The CD/HPMC/SiO2 nanosorbent has an adsorption capacity of 258 ± 4 mg/g and 168 ± 6 mg/g for lead(II) and cobalt(II), respectively. The material also displayed adequate cyclability as Co2+ and Pb2+ ions were easily removed from the sorbent surface.

Intramolecular Charge Transfer Inhibition Strategy toward a Desired Solvatochromic Fluorescent Platform: Visualization of Duple Organelles and Detection of Carbon Dioxide.

Solvatochromic fluorescent probes are crucial molecular tools to investigate and aggregate proteins' fold, visualize fine structures in biomembranes, and label different organelles in dual emission colors. However, solvatochromic fluorogens often displayed a weak emission at high polarity, hindering their bioimaging applications. To resolve this problem, herein, we propose an intramolecular charge transfer (ICT) inhibition strategy. The probe was designed with a single electronic donor and two acceptors in order to split and inhibit the ICT procedure. As a result, the probe displayed an intense emission at both low and high polarities and showed a large emission shift (84 nm) upon polarity change. Using the probe, we successfully imaged lipid droplets and the endoplasmic reticulum in different fluorescence colors. Moreover, the different degrees of lipid accumulation by oleic acid, stearic acid, and cholesterol (oleic acid > stearic acid > cholesterol) have been revealed. The lipid accumulation induced by the three lipids could be rapidly consumed under lipid-less conditions, and the lipids with stearic acid were the most difficult to be consumed. The biological results could facilitate the understanding and treatment of lipid accumulation and obesity. Furthermore, utilizing the polarity increase of diethylamine after the reaction with CO2, the ratiometric detection of CO2 has been achieved for the first time with the probe.

The mystery of water in the atmosphere of τ Boötis b continues: Insights from revisiting archival CRIRES observations

Abstract The chemical abundances of gas-giant exoplanet atmospheres hold clues to the formation and evolution pathways that sculpt the exoplanet population. Recent ground-based high-resolution spectroscopic observations of the non-transiting hot Jupiter τ Boötis b from different instruments have resulted in a tension on the presence of water vapour in the planet’s atmosphere, which impact the planet’s inferred C/O and metallicity. To investigate this, we revisit the archival CRIRES observations of the planet’s dayside in the wavelength range 2.28 to 2.33 μm. We reanalyse them using the latest methods for correcting stellar and telluric systematics, and free-chemistry Bayesian atmospheric retrieval. We find that a spurious detection of CH4 can arise from inadequate telluric correction. We confirm the detection of CO and constrain its abundance to be near solar log10(CO) = –3.44$^{+1.63}_{-0.85}$ VMR. We find a marginal evidence for H2O with log10(H2O) = –5.13$^{+1.22}_{-6.37}$ VMR. This translates to super solar C/O (0.95$^{+0.06}_{-0.31}$), marginally sub-solar metallicity (–0.21 $^{+1.66}_{-0.87}$). Due to the relatively large uncertainty on H2O abundance, we cannot confidently resolve the tension on the presence of H2O and the super-solar atmospheric metallicity of τ Boötis b. We recommend further observations of τ Boötis b in the wavelength ranges simultaneously covering CO and H2O to confirm the peculiar case of the planet’s super-solar C/O and metallicity.

IGRINS Observations of WASP-127 b: H2O, CO, and Super-solar Atmospheric Metallicity in the Inflated Sub-Saturn

High-resolution spectroscopy of exoplanet atmospheres provides insights into their composition and dynamics from the resolved line shape and depth of thousands of spectral lines. WASP-127 b is an extremely inflated sub-Saturn (R p = 1.311 R Jup, M p = 0.16 M Jup) with previously reported detections of H2O and CO2. However, the seeming absence of the primary carbon reservoir expected at WASP-127 b temperatures (T eq ∼1400 K) from chemical equilibrium, CO, posed a mystery. In this manuscript, we present the analysis of high-resolution observations of WASP-127 b with the Immersion Grating Infrared Spectrometer on Gemini South. We confirm the presence of H2O (8.67σ) and report the detection of CO (4.34σ). Additionally, we conduct a suite of Bayesian retrieval analyses covering a hierarchy of model complexity and self-consistency. When freely fitting for the molecular gas volume mixing ratios, we obtain super-solar metal enrichment for H2O abundance of log10 X H2O = −1.23 −0.49+0.29 and a lower limit on the CO abundance of log10 X CO ≥–2.20 at 2σ confidence. We also report tentative evidence of photochemistry in WASP-127 b based upon the indicative depletion of H2S. This is also supported by the data preferring models with photochemistry over free-chemistry and thermochemistry. The overall analysis implies a super-solar (∼39× Solar; [M/H] = 1.59−0.30+0.30 ) metallicity for the atmosphere of WASP-127 b and an upper limit on its atmospheric C/O ratio as < 0.68.

Visual and Gravimetric CO2 Sensing at High Humidity Levels Enabled by MOF‐804 Cofunctionalized with Ionic Liquid and m‐Cresol Purple

AbstractReal‐time monitoring of carbon dioxide (CO2) is imperative for medical diagnosis and effective environmental preservation. Despite the formidable challenge posed by the inherent chemical inertness of CO₂ molecules, a pioneering CO2 sensor based on MOF‐804 cofunctionalized with ionic liquid (IL) and m‐cresol purple (mCP) is successfully developed. By ingeniously integrating hydrogen bonding, electrostatic interactions, and hydrophobic properties within the sensitive layer, the sensor achieves a state‐of‐the‐art sensitivity (Δf = 384 Hz), an exceptionally vast detection range spanning 400–80 000 ppm, and remarkable stability with minimal sensitivity drift even at relative humidity (RH) levels exceeding 80%. Furthermore, the inherent gasochromic property, stemming from the zwitterionic mechanism, paves the way for innovative self‐sustaining CO2 test strips and groundbreaking applications, including CO2 tracking and CO2‐encrypted security labeling technology. Collectively, the realization of this ultra‐sensitive and robust CO2 monitoring approach, coupled with its CO2‐triggered visual and multifunctional capabilities, opens up novel avenues for dynamic CO2 detection, advanced military encryption strategies, and enhanced health management systems.

Gas sensitivity evaluation of decomposition gases in environmentally friendly insulating devices (C4F7N/CO2) (Chromium cluster-modified BNNTs surface interface at the atomic scale)

Under the global trend of green development, the research and development of environmentally friendly gas-insulated electrical equipment and the associated technical issues in the power systems industry have become important research topics. This study investigates the monitoring technology for decomposition gases (CO, C2F6, and COF2) under insulation defect conditions in environmentally friendly GIS equipment based on the green insulating gas mixture C4F7N/CO2. Initially, chromium clusters (Crn, n = 1–4) were used to modify one-dimensional boron nitride nanotubes (BNNTs), describing the changes in semiconductor electronic properties and magnetism at the microscopic interface. Interestingly, the electronic properties of the system changed significantly after modification, with increased electron mobility and enhanced conductivity. Subsequently, adsorption tests were conducted on three potential target gases, revealing that Cr-BNNT exhibited excellent adsorption for COF2, with an adsorption energy reaching -9.555 eV. This indicates its potential as a clean material for addressing COF2 (toxic) and CO leaks. Lastly, and most importantly, in the assessment of sensing performance, it has been discovered that Cr-BNNT holds promise as a gas sensor for C2F6. Furthermore, to meet diverse sensing requirements and environmental conditions, Cr3-BNNT and Cr4-BNNT have demonstrated potential as sensor array materials for the detection of CO (300 K, 0.145 μs) and COF2 (500 K, 3 min) gas concentrations, respectively. Our study contributes to the advancement of novel eco-friendly insulating gases and explores the use of new materials for monitoring the insulation performance and condition assessment of environmentally friendly GIS equipment.

Detection of CO2, H2S, NH3, and gas mixtures using a quartz crystal microbalance sensor array with five sensitive materials

The large-scale development of chicken farms has inevitably led to an increase in the emission of harmful gases, which has prompted rapid research development on the detection of harmful gases, such as quartz crystal microbalance (QCM) sensors. In this research, a QCM sensor array modified with ethyl cellulose (EC), polyethyleneimine (PEI), polypyrrole (PPy), tetramethylammonium fluoride tetrahydrate (TMAF), and Nitrogen-doped tungsten carbide supported on carbon nanosheets (WC@NC) was established to detect gas mixtures. By analyzing the relationship between the fundamental frequency shift and the number of sensitive material layers for the QCM sensor, the optimal number of layers was determined. The QCM sensor array consisted of a blank QCM sensor, an 8-layer EC sensor, a 4-layer PEI sensor, a 3-layer PPy sensor, an 8-layer TMAF sensor, and an 8-layer WC@NC sensor. The results showed that the PEI sensor exhibited maximum frequency shifts when detecting gases, while TMAF and WC@NC films had the highest contribution to NH3 detection. TMAF, PEI, and WC@NC played significant roles in the binary classification of exceeding the standard detection of NH3. Additionally, WC@NC and EC sensors played an important role in detecting H2S and CO2, respectively. The QCM sensor array could accurately classify the excessive state of CO2. Overall, the QCM sensor array demonstrated a correct recognition rate of 87.5 %, indicating its potential for classifying the exceedance of NH3, CO2, and H2S gases in gas mixtures. This work provides basic information for research on QCM sensor arrays in gas detection.

JWST-TST High Contrast: Spectroscopic Characterization of the Benchmark Brown Dwarf HD 19467 B with the NIRSpec Integral Field Spectrograph

We present the atmospheric characterization of the substellar companion HD 19467 B as part of the pioneering James Webb Space Telescope Guaranteed Time Observer program to obtain moderate resolution spectra (R ∼ 2700, 3–5 μm) of a high-contrast companion with the NIRSpec integral field unit (IFU). HD 19467 B is an old, ∼9 Gyr, companion to a solar-type star with multiple measured dynamical masses. The spectra show detections of CO, CO2, CH4, and H2O. We forward model the spectra using Markov Chain Monte Carlo methods and atmospheric model grids to constrain the effective temperature and surface gravity. We then use NEWERA-PHOENIX grids to constrain nonequilibrium chemistry parameterized by K zz and explore molecular abundance ratios of the detected molecules. We find an effective temperature of 1103 K, with a probable range from 1000 to 1200 K, a surface gravity of 4.50 dex, with a range of 4.14–5.00, and deep vertical mixing, log10(K zz ), of 5.03, with a range of 5.00–5.44. All molecular mixing ratios are approximately solar, leading to a C/O ∼ 0.55, which is expected from a T5.5 brown dwarf. Finally, we calculate an updated dynamical mass of HD 19467 B using newly derived NIRCam astrometry, which we find to be 71.6−4.6+5.3MJup , in agreement with the mass range we derive from evolutionary models, which we find to be 63–75 M Jup. These observations demonstrate the excellent capabilities of the NIRSpec IFU to achieve detailed spectral characterization of substellar companions at high contrast close to bright host stars, in this case at a separation of ∼1.″6 with a contrast of 10−4 in the 3–5 μm range.

Performance for CO gas sensing of janus ReSSe monolayer doped with Fe, Ru and Os from first principles calculation

Abstract Transition metal dichalcogenides (TMDs) have many excellent properties as promising class of two-dimensional materials. In this study, we conducted rigorous calculations utilizing density functional theory to evaluate the potential of Janus ReSSe monolayers, doped with transition metals such as Fe, Ru, and Os, in gas-sensitive applications specifically targeting CO detection. Three stable structures of X-Re15S16Se16 Janus doped with X elements (X = Fe, Os, Ru) were designed. Our findings indicate that the C atom of the CO molecule exhibits a higher affinity for adsorbing onto the X (X = Fe, Os, Ru) transition metal atoms, forming robust X–C bonds, rather than the O atom. Among these bonds, the Os-C bond exhibits the strongest bonding states, followed by the Ru-C bond, while the Fe-C bond behaves the weakest. Notably, the d-orbital peaks of the X (X = Fe, Os, Ru) transition metals display distinct bonding strengths with the C atom. This research may provide a theoretical foundation for the development of new gas sensors based on two-dimensional materials.

CO2 detection using In and Ti doped SnO2 nanostructures: Comparative analysis of gas sensing properties

This research explores the gas-sensing characteristics of undoped SnO2, as well as indium (In:SnO2) and titanium (Ti:SnO2) doped SnO2 nanostructures, which were synthesized using a homogeneous precipitation technique. Structural analyses indicate the presence of a tetragonal rutile phase with a preferred orientation along the (110) plane, with both doped samples showing shifts towards higher angles. Raman spectroscopy confirms the vibrational modes associated with SnO2 in both the pure and In: SnO2 samples, while the Ti: SnO2 sample reveals vibrational modes corresponding to both SnO2 and TiO2. Fourier-transform infrared (FTIR) spectroscopy indicates shifts in the O-Sn-O and Sn-O bonds in the doped samples, suggesting the effects of doping. X-ray photoelectron spectroscopy (XPS) results imply a combination of SnO and SnO2 phases in the undoped SnO2, while In: SnO2 samples display In-O bonding and the presence of metallic indium, and Ti: SnO2 shows Ti-O bonding. Scanning electron microscopy (SEM) images show agglomerated particles in the pure and In-doped samples, whereas the Ti-doped samples exhibit a flake-like structure. Transmission electron microscopy (TEM) analysis verifies the integration of dopants into the SnO2 crystal lattice, with average crystallite sizes measured at 44.46 nm for undoped, 34.06 nm for In: SnO2, and 42.63 nm for Ti: SnO2. Gas-sensing experiments for CO2 detection reveal that In: SnO2 demonstrates the most significant sensing response. These results underscore the impact of doping on the structural, morphological, and gas-sensing attributes of SnO2 nanostructures, offering important insights for the advancement of efficient carbon dioxide sensors.

The gustatory receptor BdorGr43a mediated sucrose preference in the feeding of Bactrocera dorsalis

The feeding behavior of animals is pivotal for their reproductive success and energy acquisition. In our study, we found that the Bactrocera dorsalis had a pronounced preference for sucrose among six plant-derived sugars during feeding. Then, we searched the entire genome of B. dorsalis for the gustatory receptors (Grs) responsible for sucrose sensation. Putative gustatory receptors involved in the detection of sweetness, bitterness, CO2 and other unknown functions. Together with phylogenetic analysis, expression profiling, calcium imaging, and CRISPR/Cas9 mediated mutagenesis, we found that BdorGr43a is the key receptor responding to sucrose. Our study elucidated the molecular mechanism underlying the sucrose preferences in the feeding of B. dorsalis. Meanwhile, our results will serve as a reference for the understanding of gustatory sensing in insect. Furthermore, BdorGr43a may serve as an important target for the development of food attractants against the oriental fruit fly.

Compact vertical emitting ring interband cascade lasers for isotope-resolved CO2 sensing

We present a compact vertically emitting ring interband cascade laser (ICL) with low power consumption and the possibility for seamless integration into various CO2 sensing applications. Our devices exhibit desirable performance characteristics in battery-driven handheld devices, including room temperature (20 °C) threshold currents as low as 15 mA, small footprints, and stable single-mode emission, suitable for rapid isotope-resolved CO2 detection. Through epi-down bonding with sub-micron accuracy, we achieved robust integration of substrate-emitting ring ICLs, ensuring reliability and scalability that would be required for mass production. We present comprehensive experimental results validating the efficacy of our approach, including spectral analysis and CO2 sensing capabilities with limits of detection of 24 and 13 ppmv utilizing the 12CO2 P(60) and 13CO2 R(10) transitions in the ν3 fundamental band, respectively. The demonstrated devices hold great promise for a wide range of industrial applications, including environmental monitoring, process control, and atmospheric research, where compact low-power sensors are essential.

Development of a Compact NDIR CO2 Gas Sensor for a Portable Gas Analyzer

A carbon dioxide (CO2) gas sensor based on non-dispersive infrared (NDIR) technology has been developed and is suitable for use in portable devices for high-precision CO2 detection. The NDIR gas sensor comprises a MEMS infrared emitter, a MEMS thermopile detector with an integrated optical filter, and a compact gas cell with high optical coupling efficiency. A dual-ellipsoid mirror optical system was designed, and based on optical simulation analysis, the structure of the dual-ellipsoid reflective gas chamber was designed and optimized, achieving a coupling efficiency of up to 54%. Optical and thermal simulations were conducted to design the sensor structure, considering thermal management and light analysis. By optimizing the gas cell structure and conditioning circuit, we effectively reduced the sensor’s baseline noise, enhancing the overall reliability and stability of the system. The sensor’s dimensions were 20 mm × 10 mm × 4 mm (L × W × H), only 15% of the size of traditional NDIR gas sensors with equivalent detection resolution. The developed sensor offers high sensitivity and low noise, with a sensitivity of 15 μV/ppm, a detection limit of 90 ppm, and a resolution of 30 ppm. The total power consumption of the whole sensor system is 6.5 mW, with a maximum power consumption of only 90 mW.

Practical design and implementation of IoT-based occupancy monitoring systems for office buildings: A case study

This study introduces a scalable, cloud-based approach to occupancy monitoring designed to optimize HVAC operations in office buildings. It addresses the challenges of developing and implementing a multi-parameter IoT-based occupancy monitoring system by integrating various off-the-shelf sensors—CO2, infrared (IR), motion (PIR), and door status detection—into a cohesive system. Leveraging wireless LoRaWAN and novel cloud technologies, the system ensures easy installation, efficient maintenance, and robust data management. CO2-based occupancy detection models were trained using data from a reference office and validated in another office environment. Among the various models evaluated, the four best-performing ones—Decision Trees, Random Forest, LightGBM, and K-Nearest Neighbors—were selected for integration into a multi-parameter detection system. To further enhance system performance and identify optimal sensor combinations and configurations for cost-effective and accurate occupancy detection, a data fusion methodology was employed. This methodology, validated with ground-truth data from a test bed, tested the monitoring system in different office settings, ranging from single to quadruple-occupant rooms. Integration of additional parameters into the developed data fusion approach significantly improved system performance, achieving a True Positive Rate (TPR) of 95% compared to 81% with a simple baseline data fusion method. This approach also reduced false detections during unoccupied periods, as tested in multiple rooms within the studied building, thereby enhancing the system's reliability for integration into occupancy-aware HVAC control strategies.

Design of an optical gas sensor based on chalcogenide (ChG) glass platform in the mid-infrared for detection of CO2 and CO

Design of an optical gas sensor based on chalcogenide (ChG) glass platform in the mid-infrared for detection of CO2 and CO

Spectroscopic determination of cobalt(II) ion by using azo dye of triazole derivatives

Highly efficient azo-day triazole derivatives carrying a π bond and OH electron donor groups have been designed, synthesized, and evaluated as colorimetric chemosensors for detecting metal ions in environmental samples, which was further supported by the functional theory studies and UV–Vis spectrophotometric experiment. The 4-amino-5-(2-((2,3-dimethylphenyl)amino)phenyl)-4H-1,2,4-triazole-3-thiol was directed to react with 3-nitrophenol during a diazotization type reaction to form an azo-day 4-((3-(2-((2,3-dimethylphenyl) amino)phenyl)-5-mercapto-4H-1,2,4-triazol-4-yl)diazenyl)-3-nitrophenol (Y), which have been confirmed by FTIR, 1H NMR, and could also be easily used for the detection metal ions. Compound (Y) exhibited a rapid quantitative method for the detection of Co(II) at λmax (532 nm) in an aqueous solution. The current study introduces a facile, low cost, more specific and selective chemosensor for detecting trace amounts of cobalt ions. KEY WORDS: Mefenamic acid, Azo dye, Cobalt(II), Spectroscopy Bull. Chem. Soc. Ethiop. 2024, 38(5), 1557-1567. DOI: https://dx.doi.org/10.4314/bcse.v38i6.5

Preparation of glutathione-Cu/Ag bimetallic nanoparticles for temperature and metal ion Co2+ sensing

In this work, copper silver bimetallic nanoparticles (Cu/Ag BNPs) with strong fluorescence were prepared using glutathione (GSH) as a reductant and protectant. The range of fluorescence signal of GSH-Cu/Ag BNPs to ambient temperature is 30∼90 °C has a sensitive response and can be used as a temperature sensor. The high fluorescence intensity of GSH-Cu/Ag BNPs at around 30 °C indicates that the detection of Co2+ does not require harsh temperature conditions, which could be very convenient for future practical detection work. In addition, glutathione in Cu/Ag BNPs and the synergistic effect of Cu and Ag nanoparticles in Cu/Ag BNPs can be used as a metal ion sensor for Co2+ fluorescence detection.

Gold nanoclusters and amino-modified mesoporous silica-encapsulated carbon dot fluorescence nanosensors combined with LightGBM algorithm for ultra-fast detection of Co2+

In this study, we develop a novel ratiometric fluorescent nanosensor for the detection excess Co2+ in soil. This fluorescent nanosensor is fabricated using mesoporous silica-encapsulated nitrogen-doped carbon dots (N-CDs@mSiO2) and gold nanoclusters stabilized by bovine serum albumin (BSA-AuNCs). The green fluorescence of the carbon dots within the mesoporous silica spheres (mSiO2) serves as an internal reference signal. The red fluoresence BSA-AuNCs are covalently connected onto the surface of amino-functionalized nanospheres (N-CDs@mSiO2-NH2), providing the response signal. This nanosensor has dual emission peaks at 520 nm and 650 nm under excitation wavelength of 380 nm. The addition of Co2+ to this nanosensor causes the fluorescence quenching at 650 nm while the green fluorescence at 520 nm remains unchanged, resulting in fluorescence color change from yellow to green. The developed ratiometric fluorescence nanosensor exhibits excellent selectivity to Co2+ with a range of 2.00–200.00 μM and a detection limit as low as 0.74 μM. In addition, a Co2+ prediction model is developed using the Light Gradient Boosting Machine (LightGBM) algorithm. The entire detection process is within 10 s and the model prediction value is as high as 0.991 on average. This shows that the proposed fluorescent nanosensor, optimized with the LightGBM algorithm, provides an efficient, environmentally friendly and potentially practical solution for Co2+ detection.