Portable Detection Method Research Articles

Application of Real-Time Cell Analysis Biosensor Technology for Drug Cytotoxicity Studies in Primary Lung Cancer Cells

Biosensing technologies can be used for toxicity studies on cell cultures. The xCELLigence Real-Time Cell Analysis (RTCA) system is a portable label-free detection method with the capability to analyze cellular proliferation, migration, invasion, growth, morphology states, and cytotoxicity of adherent cells in a non-invasive environment. In pharmacological context, most xCELLigence studies were done using cancer cell lines. Hypothetically, implementing the system with primary cell culture can anticipate actions in vivo better than those seen on cell lines. This could potentially provide useful information on how the drug responds to targeted cancer. In this work, we explore the usage of biosensing technology to establish a concept for high-throughput testing of chemotherapeutics agents on primary patient-derived cancer cells. Four self-established primary lung cancer cells (samples A36, A38, A39, and A40) were derived from biopsies of patients, cultured, and tested with cisplatin. The xCELLigence was used to monitor the response of primary lung cancer cells toward different concentrations of cisplatin ranging from 1 to 120 μM. Cisplatin was found to be effective at approximately 20 μM after 48 h of exposure with A38 and A39 showing drug resistance behavior at below 20 μM concentration. The IC50 values were between 22.88 to 76.22 μM. This indicates that the RTCA biosensor technology has good potential in predicting the cell’s response to chemotherapy especially when primary cancer cells are used. This approach can be the fundamental reference in the future to support personalized chemotherapy treatment by providing additional information on metastatic behavior, cytotoxic and drug-resistance effects of the cancer cells.Graphical Abstract

Low Frequency Terahertz Induced Thermoacoustic Signal Characteristics and Its Application in Solid-State Terahertz Transmitter Power Detection

According to the 2019 Federal Communications Commission (FCC) standard, the spectrum range of 6G is 95 GHz to 3 THz. Due to the higher density of 6G base station, a portable, low-cost, and real-time power detection method for transmitters is urgently needed. Therefore, we propose a real-time terahertz (THz) power detection method based on terahertz-thermoacoustic (THz-TA) effect. Using a homemade solid-state THz transmitter (center frequency = 170 GHz, maximum output power = 92.8 mW), we investigate the relationship between THz power, pulsewidth, and THz induced thermoacoustic signal, respectively. Compared with the test results of commercial THz power meter (Erickson-PM5), the feasibility of THz power detection based on THz-TA effect is proved. The experimental results show that the minimum THz power that THz-TA test platform can respond to is 2.8 mW, and the response time is about 0.25 seconds. In the range of 2.8 −92.8 mW, the amplitude of THz-induced TA signal is linear with the output power of solid-state THz transmitter (Pearson's <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</i> = 0.99571). We also note for the first time that the time interval of THz-induced TA signal is consistent with the pulsewidth of THz signal (0.5, 1, 2, and 5 μs). Therefore, THz-TA technology can not only realize the real-time detection of THz power but also measure the pulsewidth of amplitude-modulated THz signal to a certain extent. We expect that THz-TA detection method will have great potential in the real-time detection of transmitter power of 6G base station in the future.

Recombinase Polymerase Amplification Combined with Fluorescence Immunochromatography Assay for On-Site and Ultrasensitive Detection of SARS-CoV-2.

This study established a portable and ultrasensitive detection method based on recombinase polymerase amplification (RPA) combined with high-sensitivity multilayer quantum dot (MQD)-based immunochromatographic assay (ICA) to detect the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The RPA-MQD-based ICA method is reported for the first time and has the following advantages: (i) RPA is free from the constraints of instruments and can be promoted in point-of-care testing (POCT) scenarios, (ii) fluorescence ICA enhances the portability of detection operation so that the entire operation time is controlled within 1 h, and (iii) compared with common colorimetric-based RPA-ICA, the proposed assay used MQD to provide strong and quantifiable fluorescence signal, thus enhancing the detection sensitivity. With this strategy, the proposed RPA-MQD-based ICA can amplify and detect the SARS-CoV-2 nucleic acid on-site with a sensitivity of 2 copies/reaction, which is comparable to the sensitivity of commercial reverse transcription quantitative polymerase chain reaction (RT-qPCR) kits. Moreover, the designed primers did not cross-react with other common respiratory viruses, including adenovirus, influenza virus A, and influenza virus B, suggesting high specificity. Thus, the established portable method can sensitively detect SARS-CoV-2 nucleic acid without relying on equipment, having good application prospects in SARS-CoV-2 detection scenarios under non-lab conditions.

Ratiometric fluorescence probe integrated with smartphone for visually detecting lipopolysaccharide

A portable instrument-free detection method for lipopolysaccharide (LPS) analysis was developed based on dual-emission ratiometric fluorescence sensing system. Herein, red-emitting Au nanoclusters (Au NCs) were as reference probe, while blue-emitting fluorescent silica quantum dots (Si QDs) were as response probe. Additionally, the aptamer of LPS was covalently grafted to the surface of Si QDs in order to specific recognize the LPS. According to the changes of fluorescence intensityratio (FL ratio, I461 nm/I643 nm) with the concentrations of LPS, the linear equation was fitted with the range of 50–3000 ng/mL, and the limit of detection (LOD) was 29.3 ng/mL. As a practical application, this method was employed to analyze LPS in normal saline with the recovery rate of 97.7–103.8 %. The color picker platform in the smartphone was used to transform the detection picture to the process of Red, Green and Blue (RGB) for visual detection of LPS. The low-cost and easy-carry method reported here presents broad merits for the visually quantitative detection of LPS.

A novel cellulosic non‐enzymatic nanosensor based on carbon shell silver (Ag@C) nanoparticles for colorimetric detection of Chlorpyrifos in agricultural products

AbstractBackgroundThe precise detection and quantification of organophosphorus pesticides are highly required to ensure food safety. The non‐enzymatic nanosensor technology has appeared as an efficient method to replace conventional analytical techniques of pesticide detection. The utilization of carbon‐based nanomaterials and metal nanoparticles has shown great potential to develop non‐enzymatic nanosensors for the sensitive and selective sensing of food contaminants.ResultsIn this study, bifunctional carbon shell silver nanoparticles (Ag@C NPs) having oxidase‐like properties and advanced optical activities were used as nanozymes for visual detection of highly toxic organophosphorus pesticide (OP), Chlorpyrifos. The as‐prepared nanomaterial was characterized for its structural and morphological features. The nanosensor was fabricated by immobilizing Ag@C NPs in the network of sodium alginate gel over a cellulosic paper disc. The detection was based on the inhibition of oxidase‐like activity of Ag@C NPs by the adsorption of pesticide which blocks the accessibility of substrate to produce the blue‐colored product. Under the optimized conditions, the fabricated sensor showed potential analytical response for Chlorpyrifos providing a dynamic linear range from 0–350 ng/mL with a limit of detection, of 0.097 ng/mL and limit of quantification, of 0.293 ng/mL. In addition, the devised sensor was able to recover Chlorpyrifos from spiked wheat, apple, and water samples with excellent recovery percentages. Further, the constructed nanosensor exhibited excellent selectivity and specificity to Chlorpyrifos.ConclusionThe fabricated surface provides a rapid, selective, low cost and portable detection method for the real‐time detection of OP traces from food and environmental samples.

CRISPR Cas12a-based "sweet" biosensor coupled with personal glucose meter readout for the point-of-care testing of Salmonella.

Salmonella is a pathogen that comes from different animal-originated foods and poses a significant threat to human health. The present detection methods for Salmonella are time-consuming and labor-intensive and requires skilled workers and specialized instruments. In this study, the conservative invA was selected as the target gene, and a quantitative detection method for Salmonella with wide availability and user-friendliness was established based on CRISPR Cas12a and a personal glucose meter (PGM). The indirect signal transformation from the original target DNA to the final glucose signal was achieved through RAA, CRISPR Cas12a reaction, enzymic reaction, and glucose signal reading by a PGM (accu-chek type from Roche). This PGMs-CRISPR assay showed a detection sensitivity of Salmonella as low as 5 colony-forming units (CFU)/reaction in either pure culture or artificially contaminated food samples and exhibited specificity between Salmonella isolates and non-Salmonella isolates. Furthermore, quantitative detection of Salmonella in spiked milk samples was also achieved within the range from 1 to 1 × 103 CFU/reaction. Subsequently, the correlation and consistency between the PGMs-CRISPR assay and quantitative polymerase chain reaction (qPCR) in detection of Salmonella in spiked milk samples were achieved. Therefore, a highly sensitive, portable, quantitative, and user-friendly detection method based on CRISPR Cas12a and PGMs was developed in this study for Salmonella detection and identification. PRACTICAL APPLICATION: A sensitive, rapid, user-friendly, and quantitative detection method based on CRISPR Cas12a for Salmonella in food has been developed in this study, which is of great significance to food safety supervision and management.

Electrochemical detection of Zika and Dengue infections using a single chip

Zika and Dengue are infectious diseases caused by flaviviruses and transmitted by Aedes mosquitoes. Although symptoms are usually mild, complications such as dengue hemorrhagic fever and microcephaly in newborns -after the pregnant woman becomes infected with the Zika virus-have emerged as a global public health concern. The co-circulation of Zika and Dengue viruses and the overlapping of their symptoms represent a challenge for the accurate diagnosis. A single test for the point-of-care detection of both diseases is crucial. Here we report a single chip that distinguishes between Zika and Dengue infections using the non-structural protein 1 (NS1) as biomarkers. A novel multiplex electrochemical device containing four independent working electrodes was developed. Zika and Dengue biosensors were fabricated separately on different working electrodes. Selectivity tests showed that the two biosensors can distinguish not only the NS1 proteins from Zika and Dengue but also the spike proteins present in the SARS-CoV-2. This is especially relevant as patients with COVID-19 may have symptoms similar to Zika and Dengue. The gold surface was modified with cysteamine and antibodies against the NS1 proteins. Both biosensors detected their respective biomarkers at clinically relevant concentrations and presented a good linear relationship between the percentage change in impedance and the logarithm of the NS1 concentration (R2 = 0.990 for Dengue and R2 = 0.995 for Zika). Upon combining a simple sample preparation with a portable detection method, our disposable multiplex device offers a point-of-care diagnostic test for Zika and Dengue using a single chip. Additionally, two other biosensors can be added to the chip, providing a platform for viral detection.

Rapid and sensitive detection of ovarian cancer biomarker using a portable single peak Raman detection method

Raman spectroscopy (RS) is a widely used non-destructive technique for biosensing applications because of its ability to detect unique ‘fingerprint’ spectra of biomolecules from the vibrational bands. To detect these weak fingerprint spectra, a complex detection system consisting of expensive detectors and optical components are needed. As a result, surface enhanced Raman spectroscopy (SERS) method were used to increase the Raman signal multifold beyond 1012 times. However, complexity of the entire Raman detection system can be greatly reduced if a short wavelength region/unique single spectral band can distinctly identify the investigating analyte, thereby reducing the need of multiple optical components to capture the entire frequency range of Raman spectra. Here we propose the development of a rapid, single peak Raman technique for the detection of epithelial ovarian cancers (EOC)s through haptoglobin (Hp), a prognostic biomarker. Hp concentration in ovarian cyst fluid (OCF) can be detected and quantified using Raman spectroscopy-based in vitro diagnostic assay. The uniqueness of the Raman assay is that, only in the presence of the analyte Hp, the assay reagent undergoes a biochemical reaction that results in product formation. The unique Raman signature of the assay output falls within the wavenumber region 1500–1700 cm−1 and can be detected using our single peak Raman system. The diagnostic performance of our Raman system had 100.0% sensitivity, 85.0% specificity, 100.0% negative predictive value and 84.2% positive predictive value when compared to gold standard paraffin histology in a proof-of-concept study on 36 clinical OCF samples. When compared to blood-based serum cancer antigen 125 (CA125) levels, the Raman system-based assay had higher diagnostic accuracy when compared to CA125, especially in early-stage EOCs.

Hydrogen-bond activated ESIPT in naphthalimide-based fluorescent probe for sensing volatile amines

Amines levels present important indicative value in food safety and human health. Although they are involved in some normal physiological responses of the organism, their overproduction or intake may cause pathological responses. Herein, we report a recyclable visual packaging bag for volatile amines detections based on the naphthylamide derivative N-S and its positive PL characteristics. Specifically, handmade test strips based on compound N-S have been applied to fish freshness labeling, and the cyclic fumigation experiment shows its restorable PL effect and efficiency. The possible PL transfer mechanism of naphthylamide derivative N-S is uncovered by the density functional theory (DFT) calculation and titration mass spectrometer and 1H NMR. This work expands a conjugation in a molecule by hydrogen-bond activated ESIPT (H-ESIPT) and provides a portable detection method for volatile amines detection.

Clustered Regularly Interspaced Short Palindromic Repeat/Cas12a Mediated Multiplexable and Portable Detection Platform for GII Genotype Porcine Epidemic Diarrhoea Virus Rapid Diagnosis.

Porcine epidemic diarrhoea virus (PEDV) is a member of the genus Alphacoronavirus in the family Coronaviridae. It causes acute watery diarrhoea and vomiting in piglets with high a mortality rate. Currently, the GII genotype, PEDV, possesses a high separation rate in wild strains and is usually reported in immunity failure cases, which indicates a need for a portable and sensitive detection method. Here, reverse transcription–recombinase aided amplification (RT-RAA) was combined with the Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)/Cas12a system to establish a multiplexable, rapid and portable detection platform for PEDV. The CRISPR RNA (crRNA) against Spike (S) gene of GII PEDV specifically were added into the protocol. This system is suitable for different experimental conditions, including ultra-sensitive fluorescence, visual, UV light, or flow strip detection. Moreover, it exhibits high sensitivity and specificity and can detect at least 100 copies of the target gene in each reaction. The CRISPR/Cas12a detection platform requires less time and represents a rapid, reliable and practical tool for the rapid diagnosis of GII genotype PEDV.

Highly Sensitive Detection Method for HV69-70del in SARS-CoV-2 Alpha and Omicron Variants Based on CRISPR/Cas13a.

As SARS-CoV-2 variants continue to evolve, identifying variants with adaptive diagnostic tool is critical to containing the ongoing COVID-19 pandemic. Herein, we establish a highly sensitive and portable on-site detection method for the HV69-70del which exist in SARS-CoV-2 Alpha and Omicron variants using a PCR-based CRISPR/Cas13a detection system (PCR-CRISPR). The specific crRNA (CRISPR RNA) targeting the HV69-70del is screened using the fluorescence-based CRISPR assay, and the sensitivity and specificity of this method are evaluated using diluted nucleic acids of SARS-CoV-2 variants and other pathogens. The results show that the PCR-CRISPR detection method can detect 1 copies/μL SARS-CoV-2 HV69-70del mutant RNA and identify 0.1% of mutant RNA in mixed samples, which is more sensitive than the RT-qPCR based commercial SARS-CoV-2 variants detection kits and sanger sequencing. And it has no cross reactivity with ten other pathogens nucleic acids. Additionally, by combined with our previously developed ERASE (Easy-Readout and Sensitive Enhanced) lateral flow strip suitable for CRISPR detection, we provide a novel diagnosis tool to identify SARS-CoV-2 variants in primary and resource-limited medical institutions without professional and expensive fluorescent detector.

Rapid SARS-CoV-2 diagnosis using disposable strips and a metal-oxide-semiconductor field-effect transistor platform.

The SARS-CoV-2 pandemic has had a significant impact worldwide. Currently, the most common detection methods for the virus are polymerase chain reaction (PCR) and lateral flow tests. PCR takes more than an hour to obtain the results and lateral flow tests have difficulty with detecting the virus at low concentrations. In this study, 60 clinical human saliva samples, which included 30 positive and 30 negative samples confirmed with RT-PCR, were screened for COVID-19 using disposable glucose biosensor strips and a reusable printed circuit board. The disposable strips were gold plated and functionalized to immobilize antibodies on the gold film. After functionalization, the strips were connected to the gate electrode of a metal-oxide-semiconductor field-effect transistor on the printed circuit board to amplify the test signals. A synchronous double-pulsed bias voltage was applied to the drain of the transistor and strips. The resulting change in drain waveforms was converted to digital readings. The RT-PCR-confirmed saliva samples were tested again using quantitative PCR (RT-qPCR) to determine cycling threshold (Ct) values. Ct values up to 45 refer to the number of amplification cycles needed to detect the presence of the virus. These PCR results were compared with digital readings from the sensor to better evaluate the sensor technology. The results indicate that the samples with a range of Ct values from 17.8 to 35 can be differentiated, which highlights the increased sensitivity of this sensor technology. This research exhibits the potential of this biosensor technology to be further developed into a cost-effective, point-of-care, and portable rapid detection method for SARS-CoV-2.

Microfluidic technology and its application in the point-of-care testing field

Since the outbreak of the coronavirus disease 2019 (COVID-19), countries around the world have suffered heavy losses of life and property. The global pandemic poses a challenge to the global public health system, and public health organizations around the world are actively looking for ways to quickly and efficiently screen for viruses. Point-of-care testing (POCT), as a fast, portable, and instant detection method, is of great significance in infectious disease detection, disease screening, pre-disease prevention, postoperative treatment, and other fields. Microfluidic technology is a comprehensive technology that involves various interdisciplinary disciplines. It is also known as a lab-on-a-chip (LOC), and can concentrate biological and chemical experiments in traditional laboratories on a chip of several square centimeters with high integration. Therefore, microfluidic devices have become the primary implementation platform of POCT technology. POCT devices based on microfluidic technology combine the advantages of both POCT and microfluids, and are expected to shine in the biomedical field. This review introduces microfluidic technology and its applications in combination with other technologies.

Rapid Detection and Antimicrobial Susceptibility Testing of Pathogens Using AgNPs-Invertase Complexes and the Personal Glucose Meter.

Rapid detection of pathogens and assessment of antimicrobial susceptibility is of great importance for public health, especially in resource-limiting regions. Herein, we developed a rapid, portable, and universal detection method for bacteria using AgNPs-invertase complexes and the personal glucose meter (PGM). In the presence of bacteria, the invertase could be released from AgNPs-invertase complexes where its enzyme activity of invertase was inhibited. Then, the enzyme activity of invertase was restored and could convert sucrose into glucose measured by a commercially PGM. There was a good linear relationship between PGM signal and concentration of E. coli or S. aureus as the bacteria model with high sensitivity. And our proposed biosensor was proved to be a rapid and reliable method for antimicrobial susceptibility testing within 4 h with consistent results of Minimum Inhibitory Concentrations (MICs) testing, providing a portable and convenient method to treat infected patients with correct antibiotics and reduce the production of antibiotic-resistant bacteria, especially for resource-limiting settings.

Rapid detection of genetically modified products based on CRISPR-Cas12a combined with recombinase polymerase amplification

With the large-scale planting of genetically modified (GM) crops, consumers were more aware of biosafety. Onsite rapid diagnostic methods were advantageous to the regulation of GM products. In this study, a rapid, sensitive and portable detection method based on recombinase polymerase amplification were proposed based on RPA reaction and Cas12a cleavage reaction for GM ingredients, named RPA-Cas12a-GM. The results would be displayed by fluorescence signal (FS) and visual bands of lateral flow strip (LFS). RPA-Cas12a-GM method could be completed within 45 min, and the detection limit was as low as 45 copies/μL of the standard plasmid containing CP4-EPSPS gene and Cry1Ab/Ac gene. Furthermore, the detection coincidence rate of RPA-Cas12a-GM method was 100%. In conclusion, the proposed RPA-Cas12a-GM method based FS and LFS were sensitive, specific, rapid and visible for diagnosis of CP4-EPSPS gene and Cry1Ab/Ac gene without complex equipment, which provides technical support for the regulation of GM products in the field.

Clinical Application of Thromboelastography in Acute Ischemic Stroke.

Acute ischemic stroke (AIS), characterized by high morbidity and mortality, has imposed a considerable burden on society. Despite rapid development in the treatment of AIS, there is still a high risk of recurrence. Furthermore, there is a time delay in waiting for the results of conventional coagulation tests in candidate patients for intravenous thrombolysis therapy. Heterogeneous responses to antiplatelet, intravascular thrombolysis, and endovascular therapies also worsen the situation. Thromboelastography (TEG), as a global and portable detection method for hemostasis, facilitates clinicians in disease monitoring, treatment evaluation, and prognosis prediction in AIS. In this narrative review, we provided a comprehensive summary of the clinical application of TEG in ischemic stroke and gave insights to further studies.

Photothermal sensor based on water-soluble CsPbBr3@sulfobutylether-β-cyclodextrins nanocomposite using a thermometer as readout

All-inorganic perovskite quantum dots (CsPbX3 QDs) with bright photoluminescence are suitable for application in optoelectronic field, but their extreme instability and insolubility in aqueous solution limit their development in other fields. Herein, for the first time, we encapsulated CsPbBr3 QDs using sulfobutylether-β-cyclodextrins to form nanocomposite (CsPbBr3@SBE-β-CD nanocomposite) with high water solubility and stability via a host-guest interaction strategy, in which the PL intensity remained above 100% of the initial value after 3 h storage in water. Hydrogen sulfide (H2S) is known to be an important mediator of diverse cellular functions in health and in disease, which is important to develop a selective and portable detection method for H2S. The obtained CsPbBr3@SBE-β-CD nanocomposite was employed to develop a photothermal sensor for quantitative detection of H2S using a thermometer as signal readout. Specifically, the obtained CsPbBr3@SBE-β-CD nanocomposite was used as the photothermal probe while H2S acted as a switch of the photothermal probe, and the photothermal sensor was triggered by the reaction between H2S and CsPbBr3@SBE-β-CD nanocomposite. Notably, the naked eye and fluorescence spectrophotometer could also be the signal readout for this strategy, and their detection range and limit of detection were not better than those of the proposed photothermal sensor. On the basis of this H2S-triggered photothermal sensor, H2S was successfully detected at a concentration as low as 5.0 µM in organs of adult zebrafish at room temperature for 10 min. Such innovative strategy enables new opportunity for the development of affordable assays, especially as point-of-care testing in low-resource settings.

A machine learning-enhanced biosensor for mercury detection based on an hydrophobin chimera

Marine waters are becoming contaminated by diverse pollutants at a fast rate, and detection of these water pollutants has become a major concern in recent years. Among these, mercury is considered the most toxic element for human health. At present, despite the commonly used methods for its detection are accurate, they often require sophisticated equipments, have relatively high costs, are demanding and time-consuming.Herein a novel solution to detect mercury (II) pollution in sea water is proposed, and an easy and portable detection method has been developed. Indeed, a hydrophobin based chimera able to both adhere to polystyrene multiwell plates and bind mercury (II) with a consequent fluorescent decrease was designed. The chimera was the recognition element in a fluorescence-based biosensor able to detect mercury (II) in the nM range. Indeed, this biosensor specifically measure Hg2+ concentration also in the presence of other metals, reaching a limit of detection of 0.4 nM in tap water and 0.3 nM in sea water. Moreover, the developed biosensor was coupled to machine learning methodologies with the big advantage of predicting mercury concentration levels without the use of classical reader devices, thus allowing in situ monitoring of sea pollution by non-skilled personnel.

Sensitive electrochemical detection of cholesterol using a portable paper sensor based on the synergistic effect of cholesterol oxidase and nanoporous gold

As a crucial biomarker for some diseases, the determination of cholesterol in human serum is of great significance for the diagnosis and prevention of these diseases. Hence, a portable cholesterol detection method is necessary for clinical and domestic applications. Here, a portable paper sensor was designed for cholesterol detection by modifying screen-printed electrode (SPE) with nanoporous gold (NPG). To achieve the reliable cholesterol detection, a synergistic strategy was proposed based on the oxidation of cholesterol by cholesterol oxidase (ChOx) and the reduction of oxidation product (H2O2) by NPG. Compared to existing electrochemical sensors, the resulting paper sensor exhibited a wider linear response in a range from 50 μM to 6 mM as well as a higher sensitivity of 32.68 μA mM−1 cm−2 with a lower detection limit of 8.36 μM. Moreover, the portable paper sensor presented strong anti-interference capability and stability in the detection of cholesterol in human serum, and the data detected by the portable paper sensor were consistent with that obtained by an automatic biochemical analyzer. These unique performances confirmed that the proposed paper sensor was a sensitive, reliable, and portable cholesterol detection method, making it a good choice for cholesterol detection.

Identification of volatile components in the headspace of pharmaceutical-grade fentanyl

The immense potency of fentanyl and its persistent use poses great danger to abusers and law enforcement personnel. With just a few milligrams capable of causing an overdose, most agencies advise personnel to avoid handling fentanyl or related materials directly. However, there are limited field-portable and non-contact methods for the detection of fentanyl. Thus, the development of a non-contact field portable detection method is essential. To facilitate the development of a non-contact detection method, the volatile signature of fentanyl was explored using a solid phase microextraction (SPME) coupled with gas chromatography and mass spectrometry (GC–MS) method. SPME-GC–MS was used to collect and establish the vapor signature of pure pharmaceutical-grade fentanyl and diluted pharmaceutical-grade fentanyl. The collection and analysis of these vapor signatures has provided an essential stepping-stone in the future development of a non-contact vapor detection method for fentanyl.