A molecularly imprinted photoelectrochemical sensor based on the use of Bi2S3 for sensitive determination of dioctyl phthalate.

A molecularly imprinted polymer photoelectrochemical (MIP-PEC) sensor based on bismuth sulfide (Bi2S3) is described for the determination of the plasticizer dioctyl phthalate (DOP). Bi2S3 was used as the photoelectrical converter of the sensor, and visible light was utilized as the excitation source. The molecular imprinting film was prepared through the electropolymerization of monomers in the presence of DOP. Under optimal experimental conditions, the photoelectrochemical response was linearly proportional to the logarithm of the DOP concentration in the 0.5-70 pM DOP concentration range, and the detection limit was 0.1 pM. The method is highly stable and reproducible. It was applied to the determination of DOP in spiked water samples. Graphical abstract A novel molecularly imprinted photoelectrochemical sensor with high sensitivity and high selectivity based on Bi2S3 was developed for dioctyl phthalate detection. Bi2S3 was firstly used as a photoelectric converter in photoelectrochemical sensor to improve the sensitivity of the sensor. Combining photocurrent measurement with molecular imprinting technique makes the sensor highly selective.

A nanocomposite consisting of MnO2 nanoflowers and the conducting polymer PEDOT for highly sensitive amperometric detection of paracetamol.

An electrochemical sensor for paracetamol is described that consists of a glassy carbon electrode (GCE) that was modified with the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) doped with MnO2 nanoflowers. The hydrothermally synthesized MnO2 nanoflowers possess a large surface area and can be doped into PEDOT through electrochemical deposition to form a conducting polymer nanocomposite. The nanoflowers are shown to be uniformly distributed within the nanocomposite as revealed by elemental mapping analysis. The nanocomposite displays excellent catalytic activity toward the electrochemical oxidation of paracetamol. The modified GCE, best operated at a working potential of around 0.37 V (vs. SCE) has a linear response in 0.06 to 435 µM paracetamol concentration range and a very low limit of detection (31 nM at a signal-to-noise ratio of 3). The sensor exhibits excellent reproducibility and stability, and satisfying accuracy for paracetamol detection in pharmaceutical samples. Graphical abstract A highly sensitive electrochemical sensor capable of detecting paracetamol with a limit of detection down to 31 nM was developed based on MnO2 nanoflowers doped conducting polymer PEDOT.

Three-dimensional porous self-assembled chestnut-like nickel-cobalt oxide structure as an electrochemical sensor for sensitive detection of hydrazine in water samples.

Three-dimensional NiCo2O4 is a kind of superior sensing material owing to its high electron transfer capability, large available surface area and numbers of active sites. In this work, NiCo2O4 of the three-dimensional chestnut-like structure were easily achieved through a one step hydrothermal process. Afterwards, the morphology and structure were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Based on the three-dimensional porous chestnut-like NiCo2O4, an electrochemical sensor for hydrazine (N2H4) detection is fabricated. This electrochemical platform can realize good selectivity, excellent stability, high sensitivity (∼2154.4 µA mM-1 cm-2), and low detection limit (0.3 µM), as well as a wide linear range from 1 µM to 1096 µM. The synergistic effect of nickel-cobalt in such mixed transition metal oxides which Co in Co3O4 is partially replaced by Ni are beneficial for enhancing sensing properties. This study proves that three-dimensional porous chestnut-like NiCo2O4 is electrochemically active for catalytic performance which is particular and promising material for good application in the practical detection of N2H4.