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A novel electrochemical impedimetric sensor based on new copper phthalocyanine derivative-functionalized gold substrates has been developed. The modified transducers have been characterized using Fourier transform infrared spectroscopy and contact angle measurements. Under the optimized conditions in terms of polarization and frequency range, the developed sensor provided a large linear range from 1 × 10−10to 1 × 10−3 M with a detection limit of 9.48 × 10−11 M. To minimize the impedimetric sensor’s size, a microsensor based on modified gold microelectrodes was developed. Good sensitivity in the range from 1 × 10−8to 1 × 10−3 M with a limit of detection of 8.32 × 10−9 M was achieved. [ABSTRACT FROM PUBLISHER]

In this work, we report the development of a highly sensitive capacitance chemical sensor based on a copper C,C,C,C-tetra-carboxylic phthalocyanine-acrylate polymer adduct (Cu(II)TCPc-PAA) for phosphate ions detection. A capacitance silicon nitride substrate based Al−Cu/Si-p/SiO2/Si3N4 structure was used as transducer. These materials have provided good stability of electrochemical measurements. The functionalized silicon-based transducers with a Cu(II)Pc-PAA membrane were characterized by using Mott-Schottky technique measurements at different frequency ranges and for different phosphate concentrations. The morphological surface of the Cu(II)Pc-PAA modified silicon-nitride based transducer was characterized by contact angle measurements and atomic force microscopy. The pH effect was also investigated by the Mott-Schottcky technique for different Tris-HCl buffer solutions. The sensitivity of silicon nitride was studied at different pH of Tris-HCl buffer solutions. This pH test has provided a sensitivity value of 51 mV/decade. The developed chemical sensor showed a good performance for phosphate ions detection within the range of 10−10 to 10−5 M with a Nernstian sensitivity of 27.7 mV/decade. The limit of detection of phosphate ions was determined at 1 nM. This chemical sensor was highly specific for phosphate ions when compared to other interfering ions as chloride, sulfate, carbonate and perchlorate. The present capacitive chemical sensor is thus very promising for sensitive and rapid detection of phosphate in environmental applications. [ABSTRACT FROM AUTHOR]

Abstract In this work, a novel sensor based on immobilised copper phthalocyanine, 2,9,16,23-tetracarboxylic acid-polyacrylamide (Cu(II)TC Pc-PAA) was developed for determination of acid phosphatase (ACP) levels in nanomolar quantities. Detection was based on the measurement of enzymatically generated phosphate, with initial studies focused on phosphate detection at a Cu(II)TC Pc-PAA modified screen-printed gold transducer. The sensor was characterised in relation to operational performance (pH, response time, stability, linearity, and sensitivity) and common anionic interferents (nitrate, sulphate, chloride, and perchlorate). The functionalised surface also facilitated rapid detection of the enzyme bi-product 2-naphthol over the range 5–3000 μM. Quantitation of ACP was demonstrated, realising a linear response range of 0.5–20 nM and LOD of 0.5 nM, which is within the clinical range for this prostate cancer biomarker. Graphical abstract Image 1 Highlights • Phosphate determination via immobilised novel copper phthalocyanine derivative. • Acid phosphatase enzyme assay development based on dual detection of enzymatically generated phosphate and naphthol. • Detection of acid phosphatase in spiked serum samples at clinically relevant concentrations achieved. [ABSTRACT FROM AUTHOR]