Dual detection biosensor based on porous silicon substrate

Progress of porous silicon APTES-functionalization by FTIR investigations

“…Functionalized silicon structures were successfully integrated in chemical and biological microelectronic platforms. Owing to its high specific surface area and its versatile surface chemistry reactivity, PS remains a potential functionalized material for various detection devices [1][2][3][4][5] and in many medical applications [6][7][8]. Functionalization is adopted during incorporation of the recognition element and in chemical stabilization of the material surface.…”

Immobilization of hydroxocobalamin (vitamin B12) on aptes-functionalized mesoporous silicon

“…This could be due to the apparition of more insulating layers on the surface of the PS functionalized electrode [21]. The |Z| plot of the PS layer (figure 4(a)) corresponds to a one time constant [22], while plots of functionalized PS layers (figures 4(b)-(d)) are specific of a Randles Cell [22] consisting of a solution resistance R s in series with a circuit formed by an electrical double layer capacitance (existing in the interface between an electrode and its surrounding electrolyte) in parallel with a charge transfer impedance (R ct ) and a Warburg impedance (W) which accounts for the diffusion process [21][22][23][24][25]. The presence of APTES or APTES/GTA or APTES/GTA/VB12 increases R ct in presence of a Warburg line at the low frequency region (figure 5).…”

Porous Silicon Biosensors Employing Emerging Capture Probes

“…Yet, a recent study demonstrated the quenching of a reporter-label inside the porous structure in a very interesting manner [92], this work will be discussed in more detail in the next section. Fluorescent labels have also been used in assays to combine both, a fluorescent signal and reflectivity spectra [98] or electrical impedance [87], respectively. Nonetheless, label-free methods are often preferred.…”