Dendrimer Precursors for Nanomolar and Picomolar Real‐Time Surface Plasmon Resonance/Potentiometric Chemical Nerve Agent Sensing Using Electrochemically Crosslinked Ultrathin Films

Abstract

Nanomolar detection and specific recognition of pinacolyl methylphosphonate (PMP), a hydrolysis product and an analog of a relatively persistent class of toxic nerve agents, has been achieved. In addition, picomolar sensitivity is observed with methylphosphonic acid (MPA), an end‐hydrolysis product for all organophosphate‐based nerve agents. This is achieved using a combined surface plasmon resonance (SPR) and potentiometry setup. A modified polyamidoamine (PAMAM) carbazole/Cu2+ dendrimer, which is electrochemically crosslinked on a self‐assembled monolayer (SAM) modified Au substrate, is used as an active sensing element for trapping the nerve‐agent analogs. The ultrathin films have been used to study the anchoring of nerve agents via non‐covalent interactions. The carbazole to amine ratio is optimized to ensure free primary amines are available to interact with the analyte and the Cu2+ ions present in the system, which further enhances the selectivity. The carbazole group on the periphery serves a dual purpose: crosslinking the dendrimers to form a conjugated network film, and generating the potentiometric response. The adsorption kinetics are monitored by using an in situ SPR/potentiometric setup. This technique not only offers a real‐time dual detection of highly toxic nerve‐agent analogs, but also shows viability for future sensor‐device applications.

Terthiophene-Jacketed Poly(benzyl ether) Dendrimers: Sonication Synthesis, Electropolymerization, and Polythiophene Film Formation

“…There have been a few reports describing the electropolymerization of the peripheral groups on a dendrimer. For example, in one of our studies we have demonstrated the cross-linking of the peripheral carbazole groups of a carbazole-terminated PAMAM dendrimers . Similarly, Crooks et al have reported the cross-linking of thiophene-terminated PAMAM dendrimers.…”

Spacer-directed comparable and contrasting optical properties in D–A molecules enabling the fabrication of efficient novel thin-film phototransistors

“…For AnBf and CbBf , a more detailed and rather intricate synthetic plan was followed. Firstly, the aldehydes An1 and Cb1 were synthesized following methods in the literature 54–56 and were further condensed with A1 , affording AnBf and CbBf . All the compounds were characterized using 1 H NMR, 13 C, 11 B, 19 F NMR spectroscopic techniques and mass spectrometry (Fig.…”

“…The syntheses of A1 , 9-methyl-9 H -carbazole-3-carbaldehyde ( 2 ), 4-(2-(9 H -carbazol-9-yl)ethoxy)benzaldehyde ( Cb1 ) 4-(anthracen-9-ylmethoxy)benzaldehyde ( An1 ) were achieved according to previously reported procedures. 54–56…”

Nanocomposite p‐n Junction Polycarbazole CdSe/TiO2 Thin Films on ITO via Electrochemical Crosslinking

“…On the other hand, the transition for an energy transfer to a charge transport mechanism indicates a more favorable property for a PV device application 31. Other possible applications include chemical sensors based on the incorporation of analyte as part of the electropolymerization process followed by removal (similar to molecularly imprinted polymers) 71. The detection mechanism can be based on changes in the PL and charge transport properties with and without the analyte.…”