Carbon nanotube electrodes for electrochemiluminescence biosensors

The present application is based on the use of carbon nanotubes (CNTs) for biomolecular analysis using electrochemiluminescence (ECL) detection technique. For this purpose we have grown self standing cylinder-shaped blocks of multi-wall CNTs (MWCNTs) by means of a catalytic chemical vapour deposition system, fed by camphor and ferrocene gases. The blocks were subsequently back-contacted and encapsulated into epoxy resin as electrical insulator and sealant, for their use as voltammetric electrodes. A ruthenium-complex solution has been used as ECL label. It has been observed a periodical light emission that lasts for hundreds of cycles, likely due to the CNTs structure. Thanks to a data-processing algorithm which exploits this behavior, the experiments show that it is possible to obtain a great increase in detection limit as compared to the common working metal electrodes (for example Au or Pt).