Screening for cocaine on Euro banknotes by a highly sensitive enzyme immunoassay

Microfluidic electrochemical immunosensor for the trace analysis of cocaine in water and body fluids

“…As reported before, the "anti-benzoylecgonine" antibody presented high affinity for cocaine, medium affinity for benzoylecgonine and norcocaine, and low cross-reactivity to ecgonine and ecgonine methyl ester, scopolamine, or atropine (Table 1). 13 These anti-cocaine antibodies were covalently grafted on 1 μm magnetic beads using glutaraldehyde as a homo-bifunctional cross-linker between the respective amino groups on the magnetic beads' surface and the antibodies ( Figure 1A). In the control experiment by colorimetric ELISA, a significant background signal of up to 30% of the maximum was first observed, that resulted from excess free aldehyde groups from glutaraldehyde.…”

“…9,10 Numerous constituents, such as endocrine-disrupting compounds or residues from pharmaceuticals, but also seemingly more exotic ones, such as illicit drugs like cocaine, are excreted by humans. 13,14 The challenge in detecting small organic molecules like drugs, owning the most diverse chemical properties and appearing in concentrations over a broad range, has led to the development of many new analytical techniques, unfortunately often dedicated to only one compound or one family of compounds, and difficult to adapt to other targets. Alternative to water analysis, surveys on use patterns may also be conducted by the analysis of banknotes.…”

“…Alternative to water analysis, surveys on use patterns may also be conducted by the analysis of banknotes. 13,14 The challenge in detecting small organic molecules like drugs, owning the most diverse chemical properties and appearing in concentrations over a broad range, has led to the development of many new analytical techniques, unfortunately often dedicated to only one compound or one family of compounds, and difficult to adapt to other targets. 15 Promising analytical systems based on modular chemistry have appeared more recently, in which, for example, the recognition unit can be easily adapted or exchanged depending on the targeted analyte, or in which signaling-recognition tandems for specific analytes are interchangeable, opening multiplexing possibilities.…”

“…The Ab-MBs were suspended in 300 μL PBS buffer and 30 μL 1 M hydroxylamine and kept at 2-8°C. To evaluate retention of the immunocapture properties of the antibodies, the antibodydecorated magnetic beads (Ab-MBs) were subjected to a control experiment: A direct, competitive, colorimetric enzyme-linked immunosorbent assay (ELISA) was performed in a microtiter plate using an enzyme (HRP) conjugate ("tracer") used in a direct ELISA13 and two different substrates, TMB and catechol. Six μL of the Ab-MBs suspension were incubated with 100 μL of cocaine standards for 7 minutes in non-binding microtiter plates, followed by the addition of the tracer for another 7 minutes.…”

Cocaine Detection by a Laser-induced Immunofluorometric Biosensor

“…Reviews or other papers covering the detection of drugs, e.g via the testing of hair [3][4][5][6], the use of molecularly imprinted polymers [7,8], aptamers [9], ion mobility spectrometry [10,11], mass spectrometry [12][13][14][15][16], hybrid methods [17], electrochemical methods [18,19], biosensors [9,[20][21][22][23][24][25][26][27][28][29][30][31][32][33] and immunoassays [34][35][36] have been published. Quite popular in analytical chemistry was the detection of cocaine on banknotes [37][38][39][40][41][42][43][44]. It can be concluded that cocaine detection is still an active field of research and development.…”