A nonenzymatic sensor for hydrogen peroxide has been fabricated by dispersing platinum hollow nanospheres onto polypyrrole
(PPy) nanowires to form a PPy-Pt hollow sphere nanocomposite on a glassy carbon electrode. The materials were characterized
by transmission electron microscopy and scanning electron microscopy. The process and the sensor were characterized by electrochemical
impedance spectroscopy, cyclic voltammetry, and chrono-amperometry and revealed that the electrode has a large electroactive
surface area and small resistance to electron transfer. The linear range for the determination of hydrogen peroxide is from
3.5µM to 9.9mM, the detection limit is 1.2µM (S/N = 3), and the response time is 3s. The electrode exhibited good stability
and excellent repeatability.
KeywordsPolypyrrole nanowires-Pt hollow nanospheres-Nonenzymatic sensor-Hydrogen peroxide
Microchimica Acta 10/2010; 171(1):125-131. DOI:10.1007/s00604-010-0383-4 · 3.72 Impact Factor
An amperometric carcinoembryonic antigen (CEA) immunosensor was fabricated based on Prussian blue (PB), nano-calcium carbonate
(nano-CaCO3) and nano-gold modified glassy carbon electrode. First, PB as a mediator was deposited on glassy carbon electrode to obtain
a negatively charged surface. Then, positive nano-CaCO3 was adsorbed on the PB modified electrode through electrostatic interaction. Subsequently, gold nanoparticles were deposited
on the nano-CaCO3/PB modified electrode. The use of two kinds of nanomaterials (nano-CaCO3 and nano-gold) with good biocompatibility as immobilization matrixes not only provides a biocompatible surface for protein
loading but also avoids the leaking of PB. The size of nano-CaCO3 was characterized by transmission electron microscopy (TEM). The factors influencing the performance of the immunosensor
presented were studied in detail. Under the optimized conditions, cyclic voltammograms (CV) determination of CEA showed a
specific response in two concentration ranges from 0.3 to 20ng mL−1 and from 20 to 100ng mL−1 with a detection limit of 0.1ng mL−1 at a signal-to-noise ratio of 3. The immunosensor presented exhibited high selectivity, sensitivity and good stability.
Microchimica Acta 03/2009; 165(1):53-58. DOI:10.1007/s00604-008-0097-z · 3.72 Impact Factor
A novel and convenient immunosensor, based on the electrostatic adsorption characteristics between the positively charged MnO(2) nanoparticles (nano-MnO(2)) and chitosan (CS) composite membrane (nano-MnO(2) + CS) and the negatively charged prussian blue (PB), was prepared for the detection of carcinoembryonic antigen (CEA). Firstly, PB was electro-deposited on the surface of the gold electrode in the constant potential, and then nano-MnO(2) + CS was adsorbed onto PB-modified electrode surface. Subsequently, Gold nanoparticles (nano-Au) were electro-deposited on the nano-MnO(2) + CS-modified electrode to immobilize antibody CEA (anti-CEA). Finally, bovine serum albumin (BSA) was employed to block sites against nonspecific binding. In our study, cyclic voltammetry (CV) and scanning electron microscopy (SEM) were used to characterize the fabricated process of the immunosensor. The immunosensor put up a rapid response time, high sensitivity and stability. Under the optimized conditions, cyclic voltammograms(CVs) determination of CEA displayed a broader linear response to CEA in two ranges, from 0.25 to 8.0 ng/mL, and from 8.0 to 100 ng/mL, with a relative low-detection limit of 0.083 ng/mL at three times the background and noise. The originality of the preparation of the immunosensor lies in not only using the synergistic effect of two kinds of nanomaterials (nano-MnO(2) and nano-Au) to immobilize anti-CEA, but also using nano-MnO(2) + CS to furnish a media transferring electron path. What is more, the researched methodology was efficient and potentially attractive for clinical immunoassays.
Bioprocess and Biosystems Engineering 11/2008; 32(3):407-14. DOI:10.1007/s00449-008-0260-2 · 1.82 Impact Factor