Electrospun amino-containing organosilica gel nanofibers for the ultrasensitive determination of Cu(II)

Abstract

The amino-containing organosilica gel nanofibers (APTES-PVP) were successfully fabricated via one-step sol-gel/electrospinning method with aminopropyltriethoxysilane (APTES) as the silica source and polyvinylpyrrolidone (PVP) as fiber-forming agent. The properties of the electrospun nanofibers were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and cyclic voltammetry (CV). The amino-rich organosilica-nanofiber-modified Au electrode was obtained upon electrospinning APTES-PVP gel fibers on the (3-mercaptopropyl)-trimethoxysilane (MPTS) self-assembled Au electrode surface (MPTS/Au). The resultant APTES-PVP/MPTS/Au possessed abundant amino groups, which render it favorable to accumulate Cu ions inside the 3-dimensionl structure. By using square wave stripping voltammetry, the APTES-PVP/MPTS/Au delivered a very sensitive response to Cu(II) ions. Under the optimal experiment conditions, the peak current presented a good linear relationship with Cu(II) concentration in the ranges of 7.5 × 10 −12 –1.5 × 10 −9 and 1.5 × 10 −9 –7.5 × 10 −8 mol L −1 , with a detection limit of 2.6 pM (S/N > 3). The as-prepared electrode was applied for the determination of the Cu(II) in real samples, and the results were in good agreement with those from inductively coupled plasma-mass spectrometry (ICP-MS). • The organosilica gel fiber APTES-PVP was prepared by one-step sol-gel/electrospinning. • APTES-PVP/MPTS/Au electrode was formed by direct electrospinning on MPTS/Au. • The APTES-PVP/MPTS/Au is ultra-sensitive to Cu(II) measurement with wide linear ranges. • The effect of APTES content and electrospinning time on the Cu(II) response is studied. • The detection limit of Cu(II) on APTES-PVP/MPTS/Au is pretty low (2.6 pM).