Highly Selective and Quantitative Point‐of‐Care Diagnostic Method for Adrenaline

Abstract

Adrenaline, also known as epinephrine, is a neurotransmitter/hormone that is an important target in diagnostics. Development of an effective method for detecting it in the presence of other neurotransmitters is a challenging task. The electrochemical and fluorescent techniques commonly used have low selectivity in distinguishing among catecholamines. Herein, a small‐molecule organic probe with an activated furfural moiety is reported to exploit the nucleophilicity of epinephrine to generate a bright‐colored donor–acceptor Stenhouse adduct. Among nine common neurotransmitters or their analogues, only epinephrine was found to generate a unique colour change discernible with the naked eye, whereas the other ones remain unaffected. Under various in‐field detection conditions, including solution, droplet, and paper strip‐based detection, the colour change were also noticeable. The low detection limit of 1.37 nM and a limit of quantitation of 4.37 nM were achieved with simple UV/Vis methods in addition to the sub‐ppm level sensing under visual conditions with naked eyes. The probe could be used for practical colorimetric measurements as a point‐of‐care tool without any complex and expensive machinery, making this approach accessible to all. In addition, using a simple smartphone, the determination of epinephrine concentrations is possible by using machine‐learning techniques.

Meldrum’s Acid Furfural Conjugate MAFC: A New Entry as Chromogenic Sensor for Specific Amine Identification

“…Since their first demonstration, DASA have been extensively used in various applications, ranging from drug delivery, optical sensing, phase transfer catalyst recovery, liquid crystal polymer materials, and wavelength-selective photoelectric switches to material surface modification [ 45 ]. Additionally, both triene-2-ol and cyclopentenone derivatives were explored for sensing purposes, e.g., for the detection of nerve agents [ 46 ], neurotransmitters [ 47 ], and metal ions [ 18 , 48 , 49 ], as shown in Figure 2 D. In general, all activated furan which are conjugated to an electron deficient motif are capable of giving a rapid reaction with primary and secondary amines, which makes them ideal candidates for amine-sensing applications. However, among them, MAFC succeeds well in amine identification, due to its facile synthesis, robust shelf life, and ease of solubility.…”

“…( C ) Schematic comparison of molecular structure of the three DASA generations developed so far. ( D ) Molecular sensors based on activated furan and DASA derivatives [ 18 , 46 , 47 , 48 , 49 ]. Colored motifs depict the molecular scaffold of the sensor, which is actively participating in the sensing process.…”

“…However, among them, MAFC succeeds well in amine identification, due to its facile synthesis, robust shelf life, and ease of solubility. (D) Molecular sensors based on activated furan and DASA derivatives [18,[46][47][48][49]. Colored motifs depict the molecular scaffold of the sensor, which is actively participating in the sensing process.…”

Selective Sensing of Epinephrine by Phenylboronic Acid Tethered Carbon Dot

“…Moreover, this procedure lacks selectivity towards epinephrine in comparison to its structural analogues. Notably, many of the reported absorption spectroscopic methods [11–13] are non‐trivial and comprising of complex reactions despite having considerable sensitivity in few instances (Table 1, Table S1). Thus, it is desired to develop a rapid, simple, sensitive, and cost‐effective method for the quantitative and selective detection of epinephrine.…”