An ICT-based highly fluorescent isoquinoline scaffold for selective Hg(II) detection in real-water samples: Development of a smart, low-cost RGB-Arduino electronic platform.

Selective detection and quantification of Hg2+ ions is crucial to minimize health and environmental risks. Fluorescent organic small-molecule probes have been expeditiously utilized owing to their unique set of improved properties. However, isoquinoline core has not been extensively explored as a fluorescence platform partly due to synthetic challenges. Herein, a serendipitously discovered synthetic route to access a small yet highly functionalized novel isoquinoline-based probe, IQ is reported. The synthesis is achieved through the in-situ generation of ammonia, followed by intermolecular [5C + 1 N] aza-annulation reaction with a ketendithioacetal-based precursor, P-IQ. IQ displayed excellent recognition ability towards Hg2+ ions in H2O:ACN (99:1, v/v) via ICT-off fluorescent quenching behavior. Comparative FT-IR, 1H/13C NMR, mass spectral studies, and DFT analyses were carried out to validate the suggested mechanisms. Reversible studies confirm the secondary recognition effect of in-situ generated (IQ + Hg2+) complex on cysteine. The binding constant and LOD were estimated to be 3.7 × 104 M-1 and 0.86 µM, respectively. Further, IQ was utilized to evaluate the mercury ion content in real water samples demonstrating its effectiveness in water quality monitoring. The practical utility of IQ was further explored by developing TLC strips, Whatman filter-paper strips, and a low-cost, portable Arduino-based platform. Arduino microcontroller is interfaced with an RGB sensor to detect color changes and quantify mercury concentration w.r.t. RGB values.

Reliability Testing of a Low-Cost, Multi-Purpose Arduino-Based Data Logger Deployed in Several Applications Such as Outdoor Air Quality, Human Activity, Motion, and Exhaust Gas Monitoring.

This contribution shows the possibilities of applying a low-cost, multi-purpose data logger built around an Arduino Mega 2560 single-board computer. Most projects use this kind of hardware to develop single-purpose data loggers. In this work, a data logger with a more general hardware and software architecture was built to perform measurement campaigns in very different domains. The wide applicability of this data logger was demonstrated with short-term monitoring campaigns in relation to outdoor air quality, human activity in an office, motion of a journey on a bike, and exhaust gas monitoring of a diesel generator. In addition, an assessment process and corresponding evaluation framework are proposed to assess the credibility of low-cost scientific devices built in-house. The experiences acquired during the development of the system and the short measurement campaigns were used as inputs in the assessment process. The assessment showed that the system scores positively on most product-related targets. However, unexpected events affect the assessment over the longer term. This makes the development of low-cost scientific devices harder than expected. To assure stability and long-term performance of this type of design, continuous evaluation and regular engineering corrections are needed throughout longer testing periods.

Feasibility in the use of the UV-Visible region for the characterization of glucose in deionized water using Arduino 1 / Viabilidad en el uso de la región UV-Visible para la caracterización de glucosa en agua desionizada mediante Arduino 1

ABSTRACT With an estimated approximately 2 million deaths per year, diabetes is one of the top 5 deadliest noncommunicable diseases globally. Although this disease is not fatal, the degradation of the patient's health due to a bad plan to control their glucose levels can have a fatal outcome. In order to lay the foundations for the development of a device that allows estimating glucose levels in some body fluid, we present the results obtained not only for the estimation of glucose in deionized water, but also describe the development and configuration of the created device. After analyzing 50 signals obtained from 5 different glucose concentrations, the feasibility of using the developed device for the analysis is evident, since, considering the K-Nearest Neighbors (KNN) algorithm, all the signals were associated correctly to the glucose group to which they belong.

RESUMEN Con un estimado de aproximadamente 2 millones de muertes por año, la diabetes es una de las 5 enfermedades no transmisibles más mortales a nivel mundial. Aunque esta enfermedad no es mortal, el deterioro de la salud del paciente por un mal plan para controlar sus niveles de glucosa puede tener un desenlace fatal. Con el fin de sentar las bases para el desarrollo de un dispositivo que permita estimar los niveles de glucosa en algún fluido corporal, presentamos los resultados obtenidos no solo para la estimación de glucosa en agua desionizada, sino que también describimos el desarrollo y configuración del dispositivo creado. Luego de analizar 50 señales obtenidos a partir de 5 concentraciones de glucosa diferentes, se evidencia la factibilidad de utilizar el dispositivo desarrollado para el análisis, ya que, considerando el algoritmo K-Nearest Neighbors (KNN), todas las señales se asociaron correctamente al grupo de glucosa al que pertenecen.

Arduino based intra-cerebral microinjector device for neuroscience research.

Stereotaxic surgery is a less invasive form of surgery that uses a three-dimensional coordinate system to place instruments at a specific location in the brain. Through this type of surgery, one can place needles among other tools within the structures of the brain. Therefore, injections can be given in order to deliver substances that cannot cross the blood-brain barrier. The two most important parameters of the microinjection to control are volume and speed. The volume should not be so large that it displaces the brain tissue and tears it. The injection speed must also be slow so that the liquid that comes out of the syringe can diffuse into the tissue without displacing it and damaging it. Thus, the objectives of the present work are: 1) To develop not a 3D printed prototype but an end-user device. 2) The device must be for animal research only. 3) It must have the same precision in volume and speed as commercial devices. 4) It must be adjustable for microsyringes from 0.5 µl to 1 ml. 5) It must be possible to place it directly on the stereotaxic surgery apparatus and to use it separately. 6) The price must be substantially lower than that of the commercial devices.

Noninvasive Fuel Flow Monitoring System for Vented Fuel Oil Heaters.

In this work, we present hardware and firmware design and preliminary testing results for a noninvasive device for measuring fuel oil consumption in fuel oil vented heaters. Fuel oil vented heaters are a popular space heating method in northern climates. Monitoring fuel consumption is useful to understanding residential daily and seasonal heating patterns and understanding the thermal characteristics of buildings. The device is a pump monitoring apparatus (PuMA) that employs a magnetoresistive sensor to monitor the activity of solenoid driven positive displacement pumps, which are commonly used in fuel oil vented heaters. PuMA accuracy for calculating fuel oil consumption was evaluated in a lab setting and found to vary up to 7% from the measured consumption value during testing. This variance will be explored more in field testing.

A Real-Time Detection Device for the Rapid Quantification of Skin Casual Sebum Using the Oil Red O Staining Method.

The human skin sebum suggests that it (along with other epidermal surface lipids) plays a role in skin barrier formation, the moderation of cutaneous inflammation, and antimicrobial defense. Various methods have been developed for collecting and measuring skin sebum. We tested methods of detection using "color intensity", by staining the skin casual sebum. This process was conducted in three steps; first, the selection of materials for sebum collection; second, staining the collected sebum; third, the development of a device that can measure the level of stained sebum. A plastic film was used to effectively collect sebum that increased with the replacement time of the sebum. In addition, the collected sebum was stained with Oil Red O (ORO) and checked with RGB; as a result, the R2 value was higher than 0.9. It was also confirmed that the correlation value was higher than 0.9 in the comparison result with Sebumeter®, which is a common standard technology. Finally, it was confirmed that the R2 value was higher than 0.9 in the detection value using the sensor. In conclusion, we have proven the proof of concept (PoC) for this method, and we would like to introduce an effective sebum measurement method that differs from the existing method.

A novel temperature-controlled open source microcontroller based sampler for collection of exhaled breath condensate in point-of-care diagnostics.

Exhaled breath condensate (EBC) is an attractive, non-invasive sample for clinical diagnostics. During EBC collection, its composition is influenced by the collection temperature, a factor that is often not thoroughly monitored and controlled. In this study, we assembled a novel, simple, portable, and inexpensive device for EBC collection, able to maintain a stable temperature at any value between -7 °C and +12 °C. The temperature was controlled using a microcontroller and a thermoelectric cooler that was employed to cool the aluminum block holding the glass tube or the polypropylene syringe. The performance of the novel sampler was compared with the passively cooled RTube™ and a simple EBC sampler, in which the temperature was steadily increasing during sampling. The developed sampler was able to maintain a stable temperature within ±1 °C. To investigate the influence of different sampling temperatures (i.e., +12, -7, -80 °C) on the analyte content in EBC, inorganic ions and organic acids were analyzed by capillary electrophoresis with a capacitively coupled contactless conductivity detector. It was shown that the concentration of metabolites decreased significantly with decreasing temperature. The portability and the ability to keep a stable temperature during EBC sampling makes the developed sampler suitable for point-of-care diagnostics.

Pocket-Sized Portable Labs: Control Engineering Practice Made Easy in Covid-19 Pandemic Times.

New pocket-sized laboratories are proving to be an excellent tool as complementary equipment that students and lecturers can deploy to test control engineering design techniques. Here, the description and outcome results of an IFAC activity funded project entitled as Pocket-Sized Portable Labs: Control Engineering Practice Made Easy are presented. The project was executed in Portugal, from January 2021 to the end of June 2021, during the SARS-CoV2 pandemic. The global aim of this project was to motivate pre-university students to enroll in control engineering courses by showing and demonstrating that simple practical experiments may be easily accomplished using portable pocket-size laboratories.

[Control of High Voltage Pulse Generator Based on Arduino and Its Peripheral Sensors for Cell Irreversible Electroporation Test].

A project of control of a high voltage pulse generator based on Arduino and its peripheral pulse sensor and temperature sensor was proposed for cell irreversible electroporation (IRE) test. By programming Arduino board, the analog photoelectric signal and the partial voltage signal of thermistor collected by pulse and temperature sensors were converted into digital signal and temperature value. The threshold of ECG R wave (>550) and temperature threshold (<37 oC) was set as trigger condition to control an 800 W high voltage pulse generator to release a fixed period pulse. Human lung cancer cells cultured in vitro were used to test and verify, and cell staining was used to evaluate the perforation. The results showed that Arduino and its sensors were sensitive to trigger and feedback. When the high voltage pulse generator was controlled to release 100 pulses with the parameters of 600 V, 1 200 V/cm and 100 ms pulse width, more than 95% of the cells showed nonthermal irreversible electroporation.

Constant Optical Power Operation of an Ultraviolet LED Controlled by a Smartphone.

Constant light power operation of an ultraviolet (UV) LED based on portable low-cost instrumentation and a monolithically integrated monitoring photodiode (MPD) has been reported for the first time. UV light irradiation has become one of the essential measures for disinfection and sterilization. Monitoring and maintaining a specified light power level is important to meet the criteria of sterilization. We built a module composed of a monolithically integrated UV LED and MPD, a transimpedance amplifier, an Arduino Uno card, a digital-to-analog converter and a Bluetooth transceiver. An Android App that we wrote remotely controlled the UV LED module via Bluetooth. The Arduino Uno card was programmed to receive demands from the smartphone, sent a driving voltage to the LED and returned the present MPD voltage to the smartphone. A feedback loop was used to adjust the LED voltage for maintaining a constant light output. We successfully demonstrated the functioning of remote control of the App, and the resultant UV LED measured power remained the same as the setting power. This setup can also be applied to visible or white LEDs for controlling/maintaining mixed light's chromaticity coordinates or color temperature. With such controlling and internet capability, custom profiling and maintenance of precision lighting remotely would be possible.

Diseño de una interfaz gráfica orientada a la simulación de un fermentador / Design of a graphical interface oriented to the simulation of a fermenter

RESUMEN El uso de fermentadores es común en diversos procesos biotecnológicos. Actualmente, un fermentador o biorreactor tiene la capacidad de monitorear variables físicas y químicas las cuales son mostradas al operador por medio de una pantalla. Aunado a los materiales de construcción de un biorreactor, hoy en día su adquisición es costosa e inaccesible para fines educativos y de investigación. Para abordar esta problemática, se diseñó y desarrolló la interfaz Fermenta V1.0. orientada a la simulación de un bioproceso realizado por un fermentador, para realizarla se utilizó una pantalla táctil Nextion y Arduino UNO; para su programación, se implementaron los entornos de desarrollo integrados apropiados. La interfaz fue capaz de emular diferentes dispositivos electrónicos como sensores, válvulas solenoides, bombas peristálticas, iluminación y agitación. En esta primera etapa, se establece el punto de partida para facilitar el acoplamiento de la interfaz Fermenta V1.0 con diversos sensores orientados al monitoreo de un fermentador. Con la incorporación de los dispositivos electrónicos a la interfaz, se podrá adecuar al sistema (interfaz-sensores) a un proceso biotecnológico en donde se requiera el uso de un fermentador y la necesidad de monitorear temperatura, oxígeno disuelto, pH, CO2, iluminación, agitación.

ABSTRACT The use of fermenters is common in various biotechnological processes. Currently, a fermenter or bioreactor can monitor physical and chemical variables which are displayed to the operator through a screen. In addition to the construction materials of a bioreactor, nowadays its acquisition is expensive and inaccessible for educational and research purposes. To address this problem, the Fermenta V1.0 interface was designed and developed to simulate a bioprocess performed by a fermenter, using a Nextion touch screen and Arduino UNO; for its programming, the appropriate integrated development environments were implemented. The interface was able to emulate different electronic devices such as sensors, solenoid valves, peristaltic pumps, lighting, and agitation. In this first stage, the starting point is established to facilitate the coupling of the Fermenta V1.0 interface with various sensors oriented to the monitoring of a fermenter. With the incorporation of the electronic devices to the interface, it will be possible to adapt the system (interface-sensors) to a biotechnological process where the use of a fermenter is required and the need to monitor temperature, dissolved oxygen, pH, CO2, lighting, agitation.

Acústicas bioquímicas semi-automatizadas por processamento de imagem Dipstick com base em arduino / Biochemical semi-automated acoustics by Dipstick image processing based on arduino

Apesar da ampla disponibilidade de dispositivos para leitura de tiras reativas para análise de urina, falhas potenciais persistem na rotina baseada na interpretação humana. O objetivo deste estudo foi desenvolver e avaliar o desempenho de um dispositivo baseado em Arduino para a leitura semi-automática de parâmetros de fitas reativas. O parâmetro glicose de um modelo de tira reativa comercial foi analisado pelo sistema, que prevê a concentração do analito submetendo a cor observada na tira a um modelo de regressão, ajustado a um banco de dados de padrões de cores. O sistema foi avaliado através da leitura de 80 tiras com 16 amostras de concentrações aleatórias de glicose. O menor coeficiente de variação após cinco leituras replicadas foi de 4,5% e o mais alto foi de 16,6% (MSE = 68,7 mg / dL; r = 0,979). O dispositivo apresentou resultados satisfatórios mais baixos custos. Para torná-lo útil na rotina laboratorial, seriam necessárias novas experiências com outros parâmetros e outras classes de tiras reativas para análise de urina.

Although many devices are available to read urinalysis reactive strips, potential failure, based on human interpretation, persists in routine tasks. Current study develops and evaluates the performance of an Arduino-based device for the semi-automated reading of reactive strip parameters. The glucose parameter of a commercial reactive strip model was analyzed by the system, which predicts analyte concentration by submitting the color observed in the strip to a regression model, adjusted to a database of color patterns. The system was assessed by reading of 80 strips with 16 samples of random glucose concentrations. The lowest coefficient of variation after five replicated readings was 4.5% and the highest was 16.6% (MSE=68.7 mg/dL; r=0.979). The device featured satisfactory results plus low costs. To make it useful in the laboratory routine, further experiments with other parameters and other classes of urinalysis reactive strips would be necessary.

Low-Cost Benzene Toluene Xylene Measurement Gas System Based on the Mini Chromatographic Cartridge.

Benzene, toluene and xylene (BTX) are an important part of the volatile organic compounds (VOCs) to be detected and monitored in the air, due to their toxicity towards human health. One of the most reliable technique used in BTX detection is gas chromatography (GC), which presents a high sensitivity. On the other hand, it has important drawbacks, such as high costs, the need for qualified personnel and frequent maintenance. To overcome these drawbacks, this work reports the development of a low cost and portable BTX gas detection system based on a mini chromatographic cartridge, a photo ionization detector (PID), a simple control unit (based on Arduino architecture) and a mini pump. In order to separate the BTX components, we propose the use of a cartridge 80 mm in length, composed of several commercial chromatographic column sections. To test the system performances, we have injected different amounts (from about 0.3 to 5.3 µg) of benzene, toluene and xylene and two of the most frequent possible interferents (ethanol, acetone). Experimental results have shown different retention time values (i.e., 25 ± 0.5 s, 51 ± 1.2 s and 117 ± 4 s, respectively) for benzene, toluene and xylene.

Design and Development of a Low-Cost Arduino-Based Electrical BioImpedance Spectrometer.

BACKGROUND: Bioimpedance spectroscopy (BIS) is a device used to measure electrical impedance at frequencies from 0 Hz to 1 MHz. Many clinical diagnosis and fundamental researches, especially in the field of physiology and pathology, rely on this device. The device can be used to estimate human body composition, through the information of total body water, extracellular fluid and intracellular fluid, fat-free mass, and fat mass from its impedance. BIS analysis can provide physiological statuses such as ischemia, pulmonary edema, skin cancer, and intramuscular tumors. BIS is expected to be used even more widely, both for hospital or home-based use, particularly because BIS handy, compact, inexpensive, and less power-consuming with adequately accurate real-time. In previous research, the BIS design was based on the magnitude-ratio and phase-difference detection using the AD8302 gain-phase detector method which resulted in an operating range between 20 kHz and 1 MHz. However, the impedance was obtained from the logarithmic ratio magnitude which caused the device to have limited accuracy at frequencies <20 kHz. METHODS: In this research, we conduct design and development of a low-cost arduino-based electrical bioimpedance spectrometer. RESULTS: The low-cost bioimpedance spectrometry was successfully developed using AD9850 as the programmable function generator, OPA2134 as the OpAm of voltage-controlled current source, AD620A as the instrument amplifier and AD536A as the alternating current to direct current converter which could work accurately from 0 Hz to 100 kHz. CONCLUSION: The multi-frequency bioimpedance device developed in this research has the capability to safely measure the impedance of the human body due to its relatively stable electric current, which is equal to (0.370 ± 0.003) mA with frequencies ranging from 5 to 200 kHz and has an accuracy of over 90% in the frequency range of 10 Hz to 100 kHz.

A Full Technological Traceability System for Extra Virgin Olive Oil.

The traceability of extra virgin olive oil (EVOO) could guarantee the authenticity of the product and the protection of the consumer if it is part of a system able to certify the traceability information. The purpose of this paper was to propose and apply a complete electronic traceability prototype along the entire EVOO production chain of a small Italian farm and to verify its economic sustainability. The full traceability of the EVOO extracted from 33 olive trees from three different cultivars (Carboncella, Frantoio and Leccino) was considered. The technological traceability system (TTS; infotracing) consists of several open source devices (based on radio frequency identification (RFID) and QR code technologies) able to track the EVOO from the standing olive tree to the final consumer. The infotracing system was composed of a dedicated open source app and was designed for easy blockchain integration. In addition, an economic analysis of the proposed TTS, with reference to the semi-mechanized olive harvesting process, was conducted. The results showed that the incidence of the TTS application on the whole production varies between 3% and 15.5%, (production from 5 to 60 kg tree-1). The application at the consortium level with mechanized harvesting is fully sustainable in economic terms. The proposed TTS could not only provide guarantees to the final consumer but could also direct the farmer towards precision farming management.

Portable open-source autosampler for shallow waters.

Automated water sampling can be very useful, but open-source choices are limited. Here I present an autosampler which consists of a gantry robot that delivers water from a syringe pump to 24 capped 40 ml vials. The autosampler is controlled using an Android tablet automatized using Macrodroid. Three rinsing cycles ensure negligible carryover between consecutive samples. Hourly sampling from a creek under rainy conditions suggested that total organic carbon in water was diluted by the rain. Some important limitations: 1) the autosampler must be on a steady, flat, horizontal surface; 2) unattended sampling can only last as long as the batteries powering the tablet and the motors; 3) distance from the syringe pump to water cannot exceed ~2 m in height and ~4 m in length for 3 mm tubing; 4) sampling frequency does not exceed one sample every eleven minutes. However, because of its open design, the autosampler can be modified and improved to not only overcome these limitations, but also potentially expand its scope to more demanding sampling if necessary.

FINDUS: An Open-Source 3D Printable Liquid-Handling Workstation for Laboratory Automation in Life Sciences.

3D-printed laboratory devices can enable ambitious research purposes even at a low-budget level. To follow this trend, here we describe the construction, calibration, and usage of the FINDUS (Fully Integrable Noncommercial Dispensing Utility System). We report the successful 3D printing and assembly of a liquid-handling workstation for less than $400. Using this setup, we achieve reliable and flexible liquid-dispensing automation with relative pipetting errors of less than 0.3%. We show our system is well suited for several showcase applications from both the biology and chemistry fields. In support of the open-source spirit, we make all 3D models, assembly instructions, and source code available for free download, rebuild, and modification.

A custom-built low-cost chamber for exposing rodents to e-cigarette aerosol: practical considerations.

Objectives: To (1) design and build a low-cost exposure chamber system for whole-body exposure of rodents to electronic cigarette aerosol, (2) provide detailed instructions with particular focus on automated e-cigarette activation, and (3) develop a simple mathematical model for aerosol levels in the exposure chamber.Methods: We built the system with standard laboratory equipment and an open-source electronics platform (Arduino) for e-cigarette activation. Arduino is used to control a solenoid, which pushes the activation button of so-called "Mod" e-cigarettes, and a pump to move the aerosol from the mouthpiece of the e-cigarette into the chamber. For "Pods" and "Cigalikes," the solenoid is not used as they are activated by the vacuum created by the pump. Aerosol concentrations were measured with a light-scattering laser photometer.Results: The system allows varying the air exchange rate, monitoring aerosol levels, and programing arbitrary puff topography. Aerosol concentrations observed for different chamber operating conditions (puff time and period, e-cigarette power output, air exchange rate) were consistent with the mathematical model.Conclusions: Our low-cost exposure chamber can be used in animal experimental studies of the health effects of e-cigarettes. Our model allows estimating design parameters such as chamber volume, air exchange rate, and puff period.

Photogeneration of silver nanoparticles induced by UV radiation and their use as a sensor for the determination of chloride in fuel ethanol using a flow-batch system.

Photogeneration of silver chloride nanoparticles (AgCl-NPs) in fuel ethanol was used as a sensor for the spectrophotometric determination of chloride. A low-power UV radiation source (germicidal lamp) was placed close to a flow-batch chamber and a 3D-built support for the reaction chamber was used to couple fiber optic cables in the orthogonal direction with the UV-lamp beam, allowing the monitoring of nanoparticle formation in real-time using a spectrophotometer. The nanoparticles were characterized via high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, and UV-vis spectroscopy. Most of the particles exhibited a spherical shape with an average diameter of 18 nm. The absorbance maximum was observed at 440 nm and was used for chloride determination in fuel ethanol. Under the optimized working conditions, the system exhibited a linear response from 0.05 to 0.8 mg L-1 chloride, with a limit of detection (95%) and coefficient of variation (n = 8) were estimated to be 12 µg L-1 chloride and 2.2%, respectively. The intra- and inter-day precisions (coefficient of variation) were 2.4% and 2.8%, respectively. This working range (0.05-0.8 mg L-1) for the determination of chloride at low concentrations met the limit required by Brazilian legislation (limit of 1.0 mg kg-1). Analyses of fuel ethanol were performed without sample treatment and the obtained results were compared with those obtained by ion-chromatography. No significant differences were observed between the two methods at the 95% confidence level.

Detection of Volatile Compounds Emitted by Bacteria in Wounds Using Gas Sensors.

In this paper we analyze an experiment for the use of low-cost gas sensors intended to detect bacteria in wounds using a non-intrusive technique. Seven different genera/species of microbes tend to be present in most wound infections. Detection of these bacteria usually requires sample and laboratory testing which is costly, inconvenient and time-consuming. The validation processes for these sensors with nineteen types of microbes (1 Candida, 2 Enterococcus, 6 Staphylococcus, 1 Aeromonas, 1 Micrococcus, 2 E. coli and 6 Pseudomonas) are presented here, in which four sensors were evaluated: TGS-826 used for ammonia and amines, MQ-3 used for alcohol detection, MQ-135 for CO2 and MQ-138 for acetone detection. Validation was undertaken by studying the behavior of the sensors at different distances and gas concentrations. Preliminary results with liquid cultures of 108 CFU/mL and solid cultures of 108 CFU/cm2 of the 6 Pseudomonas aeruginosa strains revealed that the four gas sensors showed a response at a height of 5 mm. The ammonia detection response of the TGS-826 to Pseudomonas showed the highest responses for the experimental samples over the background signals, with a difference between the values ​​of up to 60 units in the solid samples and the most consistent and constant values. This could suggest that this sensor is a good detector of Pseudomonas aeruginosa, and the recording made of its values ​​could be indicative of the detection of this species. All the species revealed similar CO2 emission and a high response rate with acetone for Micrococcus, Aeromonas and Staphylococcus.