Dual-signal Probe Research Articles

A novel “ON-OFF-ON” colorimetric and fluorescence dual-signal sensing APAP based on TSPP-Fe3+

Acetaminophen, also known as paracetamol (APAP), is a commonly used over-the-counter medication that is often used to treat headaches, toothaches, joint pain, muscle pain, and to lower body temperature. However, overdose can lead to liver damage, gastrointestinal distress, kidney damage, and cardiovascular disease. Therefore, it is very important to establish a method to quickly detect APAP. A novel “ON-OFF-ON” colorimetric and fluorescence dual-signal sensing system was constructed for the quantitative detection of APAP based on 5,10,15,20-tetrakis(4-sulphonatophenyl) porphyrin (TSPP) dual-signal probe. The absorbance and fluorescence intensity of TSPP respectively were quenched when Fe3+ was introduced into TSPP solution. At this point, the color of the corresponding solution changed from red to green. The absorbance and fluorescence intensity of TSPP respectively were restored when APAP was added to the TSPP-Fe3+ system. At this time, the color of the solution changed from green to colorless. Therefore, an “ON-OFF-ON” dual-signal sensing study of APAP were constructed using TSPP as the colorimetric and fluorescent probe. The proposed colorimetric sensing system had a wide linear range in the 13.12 mM ∼ 23.20 mM with 0.11 mM of limit of detection (LOD, S/N = 3). And the proposed fluorescence sensing system had a wide linear range in the 3.45 mM ∼ 12.50 mM and 41.67 mM ∼ 65.22 mM with 0.83 mM of limit of detection (LOD, S/N = 3). The dual-signal sensing system were applied to the APAP detection of real samples.

A dual-mode biosensor based on CdIn2S4 hollow microsphere combined with Au@CuO/Cu2O nanozyme for sensitive detection of Sa-16S rDNA

A dual-mode biosensor used CdIn2S4 hollow microspheres as electrochemiluminescence (ECL) and photoelectrochemistry (PEC) dual signal probes combined with Au@CuO/Cu2O nano-enzyme catalysis was fabricated for sensitive detection of Sa-16S rDNA. Firstly, CdIn2S4 microspheres displayed excellent ECL and PEC signals, then the target Sa-16S rDNA introduced a large number of Au@CuO/Cu2O nanoparticles to the electrode via Exo-III amplification strategy. Au@CuO/Cu2O is a highly efficient peroxidase mimicase, and can effectively promote H2O2 to produce ·OH, which further oxidized 4-chloro-1-naphthol (4-CN) to produce a large amount of insoluble precipitate on the electrode surface, then significantly reduced the PEC and ECL signals of CdIn2S4 for target detection. This study opens up a new multifunctional photoelectric microspheres and a flexible biosensor by using CdIn2S4 and nanozymes, showing a new channel for the detection of DNA molecules and providing valuable insights for the development of PEC biosensing technologies based on nanozymes.

Nitrogen and Chlorine Co-Doped Carbon Dots with Yellow-Green Emission as a Ratiometric Fluorescent and Colorimetric Dual-Signal Probe for Quercetin Detection and Cell Imaging

Despite the emergence of numerous carbon dots (CDs)-based sensors, most of them are fluorescent probes. To improve the reliability of the results, using ratiometric fluorescence/UV-vis absorption dual-signal probes is an effective method. Herein, nitrogen and chlorine co-doped carbon dots (N, Cl-CDs) with yellow-green fluorescence were prepared and used as a dual-function probe for ratiometric fluorescence/UV-vis. The detection range of the fluorescence method was 0.05–78[Formula: see text][Formula: see text]M, and the limit of detection (LOD) was 1.2[Formula: see text]nM (3[Formula: see text]/s). For the colorimetric method, the linear range was 0.05–186[Formula: see text][Formula: see text]M with LOD of 10.7[Formula: see text]nM. Importantly, the N, Cl-CDs were successfully used to detect Quercetin (QT) in actual water samples. Besides, due to their good biocompatibility, the N, Cl-CDs were applied to in vivo biological imaging of oocysts and shown the potential for environmental survey and biological assay.

A difunctional fluorescent probe to detect hypochlorite and hydrogen sulfide ions in ferroptosis and oxidative stress induced by Aspirin

HOCl and H2S frequently coexist in living cells and work in concert to maintain the redox dynamic balance in vivo. It is challenging to precisely and simultaneously trace both HOCl and H2S using a single recognition-type fluorescence probe. Here, a novel fluorescent probe (MB-HS) for the selective detection of hydrogen sulphide (H2S) and hypochlorous acid (HOCl) has been established based on the coupling of the methylene blue fraction and the indolium fraction. For HOCl, the dual-signal probe MB-HS displays quick turn-on fluorescence responses. However, for H2S, it exhibits turn-off fluorescence at 586 nm and turn-on at 513 nm, respectively. MB-HS showed many advantages such as quick response, strong selectivity, and high sensitivity. It was effectively used to detect endogenous HOCl/H2S in ferroptosis and oxidative stress induced by Aspirin in HepG-2 cells.

Cobalt-nitrogen co-doped carbon dots for the colorimetric and fluorometric dual-mode detection of gallic acid

Gallic acid (GA), widely used in food and medicine production industries. Herein, a kind of newly synthesized cobalt-nitrogen co-doped carbon dots (Co,N-CDs) with dual functional properties of oxidase-like activity and photoluminescence property could oxidize the 3,3′,5,5′-tetramethylbenzidine (TMB) to oxTMB with a new absorption peak at 653 nm. In addition, it was found that oxTMB performed a fluorescence-quenching effect on Co,N-CDs at 440 nm attributed to FRET (Fluorescence resonance energy transfer). Reductive GA could reduce oxTMB to TMB, weaken the blue color, and restore the fluorescence of Co,N-CDs. Thus, a colorimetric and fluorometric method for dual-mode detection of GA was established. The synthesis of the dual-signal probe was completed with a single and environmental precursor in just one step. Simultaneously, the dual-mode detection reduced detection limits, broadened the linear range and improved anti-interference ability. This method exhibited a satisfactory application prospect in the actual detection of GA in tea beverages.

Construction of a novel fluorescent probe for sensitive determination of glyphosate in food and imaging living cells.

Glyphosate is a widely used broad-spectrum herbicide in agriculture and horticulture to control a variety of weeds and undesirable plants. However, the excessive use of glyphosate has raised a number of environmental and human health concerns. It is urgent to develop tools to detect glyphosate. Herein, a novel dual-signal probe CCU-Cu2+ was designed and synthesized on the basis of CCU. CCU exhibited excellent selectivity and great sensitivity for Cu2+ which were based on both fluorescence "turn-off" reaction and comparative color visualisation methods. Due to the strong chelating ability of glyphosate on Cu2+, the CCU-Cu2+ complex was applied to glyphosate detection in practical samples. The experimental results in vitro showed that the CCU-Cu2+ complex was highly selective and rapid, with a low detection limit (1.6 μM), and could be recognised by the naked eye in the detection of glyphosate. Based on the excellent properties of the CCU-Cu2+ complex, we also constructed a smartphone-assisted detection sensing system for glyphosate detection, which has the advantages of precision, sensitivity, and high interference immunity. Moreover, the CCU-Cu2+ complex was also successfully employed for exogenous glyphosate imaging in living cells. These characteristics demonstrated that CCU-Cu2+ holds significant potential for detection and imaging of glyphosate in bio-systems.

Detection of Covid-19 with Dual-Signal Probes in Paper Microfluidics

Current Covid-19 detection methods commercialized today that use colorimetric probes havethe advantage of short response time but the issue of low sensitivity. Other methods considerfluorescent probes that increase sensitivity but lead to longer response times. In this work,both fluorescence probes and colorimetric probes are integrated into a microfluidic paper strip.Both probes are incorporated into a single microfluidic paper strip to optimize sensitivity andefficiency. As a result, the use of colorimetric probes allows for the advantages of antibodyabsorption to be utilized for a short response time to detect antigens without need an extraexcitation source while fluorescent probes increase detection sensitivity and compensate forthe low sensitivity of colorimetric probes. The dual-signal probe displays capacity for greatlyimproving the accuracy and timeliness of standard Covid-19 detection in test kits.

A colorimetric/electrochemical sensor based on coral-like CuCo2O4@AuNPs composites for sensitive dopamine detection.

As a central neurotransmitter, DA (dopamine) plays a vital part in human metabolism, and its accurate detection is of great significance in disease diagnosis. In this work, we used Cu/Co bimetallic metal-organic frameworks (MOFs) as templates and gold nanoparticles (AuNPs) to construct novel nanocomposite coral-like CuCo2O4@AuNPs with strong peroxidase activity and electrochemical response. The coral-like CuCo2O4@AuNPs showed excellent peroxidase activity, and the Km value was as low as 0.358mM. In the presence of H2O2, the colorless substrate 3,3',5,5', -tetramethylbenzidine (TMB) can be catalytically oxidized into a blue product. Simultaneously, coral-like CuCo2O4@AuNPs, as an electroactive substance, possess strong electrocatalytic activity, which enhances the electron-transfer rate and promotes excellent current response. In the presence of DA, coral-like CuCo2O4@AuNPs can catalyze the oxidation of DA to dopaquinone, which further enhances the electrochemical signal. In addition, DA captures hydroxyl radicals and inhibits the oxidation of TMB, resulting in an obvious color change (blue turns colorless) and realizing colorimetric detection with the naked eye. On this basis, we successfully established a dual-mode colorimetric/electrochemical sensor using coral-like CuCo2O4@AuNP nanocomposites as a dual-signal probe. Combining colorimetric and electrochemical detection, the sensor achieved a wide linear range (0-1mM) and a low detection limit (0.07μM) for DA concentration. It was also successfully used for the detection of DA in human serum and urine with good results. In summary, this work provides an intuitive, economical, sensitive, and promising platform for DA detection.

Dual-responsive amplification strategy for ultrasensitive detection of norovirus in food samples: Combining magnetic relaxation switching and fluorescence assay

Ultra-sensitive, accurate, and specific diagnostic probes are urgently developed to overcome the limitations of conventional norovirus (NV) probes. Herein, we presented the fabrication of a dual-signal probe using multifunctionalized gold and magnetic nanoparticles hybrid composite (Fe3O4 @Au NPs) carriers for the specific detection of NV by magnetic relaxation-fluorescence bimodal sensing. The dual-specific probes were created by modifying Fe3O4 @Au NPs with antibody (Ab) and aptamer-FAM. The antigen-Ab immunoreaction caused aggregation of Fe3O4 @Au NPs, altering the magnetic relaxation signal; simultaneously, the aptamer-FAM that were originally adsorbed on the Au surface were desorbed and cleaved into the solution in the presence of NV, causing a change in the fluorescence signal. Ultrahigh detection sensitives of 0.38 and 3.45 pg/mL were obtained for the dual-modality detection platform, respectively. Furthermore, two quantitative methods obtained satisfactory spiked recoveries for NV-spiked oyster, scallop, strawberry, and tomato samples, consistent with the results of commercial ELISA kits. The results indicated that this dual-specificity assay not only was ultrasensitive but also markedly boosted analysis reliability and precision. Hence, the dual-mode biosensor exhibits high potential for NV detection in the field of food safety.

Polydopamine-coated two-dimensional nanomaterials as high-affinity photothermal signal tag towards dual-signal detection of Salmonella typhimurium by lateral flow immunoassay

Lateral flow immunoassay (LFIA) with gold nanoparticles (AuNPs) as signal reporters has been extensively utilized for the rapid detection of foodborne pathogens. Nevertheless, it’s challenging for LFIA to obtain sensitive detection, because of the inefficient coupling of AuNPs and antibodies and the poor colorimetric signals. To improve on this, we used a two-dimensional nanomaterial (Cu2MoS4) modified with PDA (CMS@PDA) that provides superior bio-affinity and excellent photothermal signal qualities. With the CMS@PDA material, we successfully constructed a portable LFIA device for specific detection of Salmonella typhimurium (S. typhimurium) using a dual-signal probe that combines colorimetric and photothermal signals (CM/PT). The dynamic detection range of the CMS@PDA-LFIA is 103 to 107 cfu mL−1. Notably, the detection limit of 103 cfu mL−1 is 100 times more sensitive compared to AuNPs-based LFIA. Moreover, the assay exhibits satisfactory recovery rates for S. typhimurium detection in food samples. In this research, the coating of PDA solves the problem of low water-solubility of CMS, making the proposed CMS@PDA nanocomposite showcase better performance in the CM/PT mode detection by LFIA. Beyond all doubt, this work offers a novel supplement for applying multifunctional two-dimensional nanomaterials in LFIAs.

A novel colorimetric/fluorescent dual-signal probe based on silver nanoparticles functionalized with L-cysteine and rhodamine 6G derivatives for copper ion detection and cell imaging

The dual-signal probe utilizing functionalized silver nanoparticles (AgNPs) is a promising sensing tool. Herein, a novel colorimetric/fluorescent dual-signal probe (AgNPs-L-Cys-Rh6G2) was fabricated for copper ion (Cu2+) detection and cell imaging by using L-cysteine as a “bridge” to connect AgNPs and rhodamine 6G derivatives. The AgNPs-L-Cys-Rh6G2 probe exhibits a dual-signal response to Cu2+ due to Rh6G2 hydrolysis, resulting in a high fluorescence response and a significant change in color from light yellow to pink under sunlight. The linear detection ranges of the AgNPs-L-Cys-Rh6G2 probe for Cu2+ were 100–450 μM and 150–650 μM using fluorescent and colorimetry methods, respectively. The detection limits were as low as 0.169 μM and 1.36 μM, respectively. Meanwhile, the proposed probe was applied to detect Cu2+ in the actual sediment with satisfactory recovery and low relative standard deviation. Furthermore, the probe was further employed for fluorescence imaging in HeLa cells. In brief, the developed AgNPs-L-Cys-Rh6G2 sensing platform can be used for simultaneous Cu2+ determination and cell imaging.

Dual emission N-doped carbon dots as a ratiometric fluorescent and colorimetric dual-signal probe for indigo carmine detection

Novel dual-emission fluorescent nitrogen-doped carbon dots (N-CDs) were synthesized by a facile one-pot hydrothermal method using ascorbic acid and rhodamine B as precursors and melamine as nitrogen source. The obtained N-CDs exhibited dual-emitting peaks at 435 nm and 578 nm under the single excitation of 350 nm. The fluorescence at 578 nm was more effectively quenched by indigo carmine (IC) based on the internal filtration effect and aggregation-induced emission quenching. Meanwhile, the apparent color change of N-CDs from pink to blue-purple after adding various concentrations of IC could be clearly observed with the naked eye. Therefore, a ratiometric fluorescent and colorimetric dual-signal probe based on N-CDs was developed for IC detection with high selectivity and sensitivity. The addition of IC caused the ratiometric fluorescent value (F435/F578) to increase linearly within the range from 0 to100 µM with a detection limit (LOD) of 0.18 µM and the colorimetric signal presented a linear response in the range of 0–133 µM with a LOD of 57.4 nM. Furthermore, the IC in juice drink, candy, and water was successfully detected. Besides, the N-CDs were also designed as a ratiometric temperature probe, and the ratiometric fluorescence signal (F435/F578) was linearly and reversibly responsive to temperature in the range of 20–75 °C.

Dual-template molecularly imprinted electrochemical biosensor for IgG-IgM combined assay based on a dual-signal strategy

Detection of immunoglobulins (Igs) is of clinical significance for early diagnosis and timely treatment of diseases. Herein, a dual-template molecularly imprinted (DTMI) electrochemical biosensor was developed for IgG-IgM combined assay. In this DTMI electrochemical biosensor, Prussian blue (PB) and thionine (TH) decorated on graphene oxide (GO) and multi-walled carbon nanotubes (MWCNTs), respectively, were utilized as the dual-signal probes, and Au nanoparticles (AuNPs) were used for Igs anchoring and signal amplification. Polypyrrole (PPy) was electrodeposited on the biosensor surface and acted as the molecularly imprinted polymers (MIPs). After the removal of the IgG and IgM templates, the resultant DTMI electrochemical biosensor was used for IgG-IgM combined assay, and the concentrations of IgG and IgM could be indicated by the changes in the peak currents of PB (ΔIPB) and TH (ΔITH), respectively. The DTMI electrochemical biosensor displayed a wide linear range and a low limit of detection (LOD) for both IgG (28.80 pg mL−1) and IgM (0.58 pg mL−1). Finally, the developed DTMI biosensor was used for IgG-IgM combined assay in clinical serum samples, and the results were comparable to those obtained by conventional immunoturbidimetry, implying its great potential in clinical diagnosis.

RETRACTED: A FRET-based dual fluorescent probe with nitrogen doped carbon dots as the energy donor for selective detection of Fe3+

• A selective Fe 3+ detection method based on FRET between nitrogen doped carbon quantum dots (N-CQDs) and Rhodamine B (RhB) was constructed. • The occurrence of FRET was verified by Förster theory. Both the emission peaks of N-CQDs and RhB show selective detection ability for Fe 3+ ions. • This FRET-based sensing system shows high sensitivity at low Fe 3+ concentration with a limit of detection of 1.47 nM. In this work, a Fe 3+ detection method based on FRET system via nitrogen doped carbon quantum dots (N-CQDs) and Rhodamine B (RhB) was constructed. In this system, N-CQDs served as the donor whereas RhB served as the acceptor. The distance between the chosen D-A pair was determined to be 4.91 nm according to Förster theory. Only the presence of Fe 3+ hampered the FRET process and deactivated the electronic excitation energy of RhB. A dual-signal probe (RhB@N-CQDs) for selective detection of Fe 3+ was developed with a limit of detection of 1.47 nM to overcome the shortcomings of traditional detection methods at low concentrations.

A methylene blue and Ag+ ratiometric electrochemical aptasensor based on Au@Pt/Fe-N-C signal amplification strategy for zearalenone detection

Zearalenone (ZEN) contamination has attracted global attention of the food industry because of its toxicity to human body, so sensitive and rapid ZEN assays are critically important. Herein, methylene blue (MB) and Ag+ were used as dual-signal probes to design a ratiometric electrochemical aptasensor for facilely and accurately detection of ZEN, and an Au@Pt/Fe-N-C nanocomposites-induced signal amplification strategy was introduced to improve the sensitivity of the aptasensor. The Au@Pt/Fe-N-C nanocomposites had larger surface area and higher conductivity than single component materials. Firstly, DNA1 was modified on the gold electrode (AuE), so the signal probe Ag+ can produce a strong IAg+ by forming C-Ag+-C structure with DNA1. Simultaneously, the system MB-Au@Pt/Fe-N-C-dsDNA (containing aptamer and DNA2) cannot modify to AuE to obtain IMB. The aptasensor was incubated with ZEN that can compete with aptamer, and the released MB-Au@Pt/Fe-N-C-DNA2 can be modified on AuE by hybridization between DNA1 and DNA2, so as to generate a strong IMB. Au@Pt or Fe-N-C. The intensity of IAg+ decreased because it cannot combine with DNA1. The signal ratio IMB/IAg+ exhibited a good linear relationship with lgCZEN in the concentration of ZEN in the ranging of 1 × 10−5-10 ng/mL, and the limit of detection (LOD) and limit of quantitation (LOQ) were calculated as 5 fg/mL and 16.7 fg/mL, respectively. The successfully determination of ZEN in corn flour samples demonstrated that the ratiometric electrochemical aptasensor had excellent veracity, reliability and potential application prospects.

Ratiometric electrochemical immunoassay for procalcitonin based on dual signal probes: Ag NPs and Nile blue A.

In order to determineprocalcitonin, a sandwich-type ratiometic electrochemical immunosensor was developed by differential pulse voltammetry (DPV).Dueto high chemical stability and good biocompatibility, graphitic carbon nitride (g-C3N4) could be used as feasible supporter to carry silver nanoparticles (Ag NPs) with an obvious oxidative peak (measured typically at + 0.3V vs. SCE). Ag NPs loaded onto g-C3N4 were not only beneficial to prevent the agglomeration of Ag NPs, but also favorable to improve the electron transfer velocity of g-C3N4. Moreover, the g-C3N4-Ag NPs as the matrix could immobilize primary antibody by Ag-N bond. Nile blue A (NBA), an excellent redox probe based on the redox reaction with two-electrons, provides a current signal at - 0.38V (vs. SCE). Zr-based metal organic framework (UiO-67), an ideal framework material with large specific surface area and high porosity, could absorb the substantial water-soluble NBA by electrostatic adsorption. TheUiO-67 modified by NBA (NBA-UiO-67) owned admirable biocompatibility and was a qualifying marker to load the secondary antibody. For the immunosensor, the current ratio of NBA to Ag NPs (INBA/IAg NPs) was increased as the concentrations of PCT increased. Under the optimum conditions, the linear range of the immunosensor was 0.005 to 50ng/mL; the detection limit was 1.67pg/mL (S/N = 3), which reflected the excellent analytical performance of the sensor. The proposed immunosensor strategy isa simple and dependable platform, with great application potential in biometric analysis.

A corrole-based fluorescent probe for detection of sulfur ion and its application in living cells

A dual signaling probe DPC-O-NBD formed through the conjugation of 5,15-bis(phenyl)-10-(4-hydroxylphenyl)-corrole (DPC-OH) with 4-chloro-7-nitrobe-nzo-2-oxa-1,3-diazole (NBD-Cl) is explored to detect sulfur ion (S2−). The key design principle is based on the nucleophilicity of S2−, which can be used to cleave the bridging ether bond in the probe to obtain both fluorogenic and chromogenic signaling behaviors. Importantly, the probe DPC-O-NBD not only showed a high sensitivity (LOD: 48 nM) and selectivity over other interfering species, but also exhibited a rapid response (∼18 s) towards S2−. Furthermore, DPC-O-NBD can also be used to detect S2− in both water and live cells, providing a potentially powerful approach for probing S2− chemistry in biological systems.

Individual and successive detection of H2S and HClO in living cells and zebrafish by a dual-channel fluorescent probe with longer emission wavelength

Reactive oxygen species (ROS) and reactive sulfur species (RSS) participate in many physiological activities and help maintaining the redox homeostasis in biological system. The complicated intrinsic connection between specific ROS/RSS needs to be further explored. Herein, a novel fluorescent probe (MB-NAP-N3) with longer emission wavelength has been rationally designed and synthesized based on the conjugation of the methylene blue moiety and the naphthalimide moiety for the detection of hypochlorous acid (HClO) and hydrogen sulfide (H2S). The dual-signal probe exhibits rapid turn-on fluorescence responses for individual and successive detection of H2S and HClO in green and red channels, respectively. Owning to its advantages such as fast response, good selectivity and high sensitivity, the probe was successfully applied to detect endogenous and exogenous HClO/H2S in living cells. Furthermore, the outstanding luminescence performance makes it suitable for the visualization of the in vivo interaction between the two analytes in zebrafish.

A photoelectrochemical/colorimetric immunosensor for broad-spectrum detection of ochratoxins using bifunctional copper oxide nanoflowers

Abstract The detection of ochratoxins is of great significance for rapid and accurate food safety screening. This work was aimed to design a photoelectrochemical/colorimetric immunosensor for the broad-spectrum detection of ochratoxin A (OTA), ochratoxin B (OTB) and ochratoxin C (OTC). In order to provide a comprehensive and accurate assessment of ochratoxins contamination, the broad spectrum antibodies were used as recognized elements and the bifunctional copper oxide nanoflowers (CuO NFs) were used as dual-signal probe to trigger the response of photoelectrochemical (PEC) and colorimetric detection. In PEC mode, Cu2+ released by CuO NFs can replace Cd2+ in photoactive material to form a new band gap, which accelerated the electron-hole recombination to change the PEC current. In colorimetric mode, Cu2+ efficiently assisted etching of Au nanorods (Au NRs), causing multiply color changes and localized surface plasmon resonance (LSPR) shifts of Au NRs. Two independent modes from different detection mechanisms were used to reflect the concentrations of ochratoxins with more accuracy and reliability. Therefore, this work not only realized the broad-spectrum detection of OTA, OTB and OTC, but also provided a new strategy for the development of accurate, visual and multi-signal immunosensing platform.

Dual signaling of thallium(III) ions via oxidative cleavage of a sulfonhydrazide linkage

The thallium is widely used in various research and industrial applications but is very toxic. In this work, we developed a novel reaction-based dual signaling probe for the selective and sensitive determination of Tl3+ via the oxidative cleavage of a rhodamine–dansylhydrazide conjugate. The designed probe showed pronounced colorimetric and fluorescence signaling behavior toward Tl3+ with a detection limit of 1.3 × 10–7 M (0.027 ppm), as well as selectivity over other common metal ions, anions, and oxidants. The Tl3+ signaling process required less than 2 min and was not influenced by the solution pH within the range of 4.0–5.5; however, the signal diminished significantly above pH 6.0. To demonstrate the practical applicability of the designed probe, a simple and convenient colorimetric assay for the determination of Tl3+ in commercial reagents was established using an office scanner as a readily available signal capturing device.