Method and device for cleaving and/or sequencing a peptide

A method for sequencing a peptide, comprising:

• providing a series of reaction cells, each reaction cell of the series configured as an electrochemical transducer translating an applied voltage or current into a change of pH within the reaction cell and having arranged therein a sample surface, the sample surface being functionalised with moieties suited for the sequential removal of an amino acid from a terminus of the peptide, the terminus being the N-terminus or the C-terminus of the peptide;
• a) introducing the peptide into a first reaction cell of the series of reaction cells;
• b) adjusting the pH in the first reaction cell to attach the peptide with the terminus to the sample surface of the first reaction cell;
• c) removing non-attached peptide from the first reaction cell;
• d) adjusting the pH in the first reaction cell to separate an amino acid at the terminus of the peptide from the peptide and to immobilize the amino acid on the sample surface of the first reaction cell;
• sequentially repeating steps a)-d) in further cells of the series of reaction cells, each time using the remainder of the peptide from the preceding reaction cell.

A microfluidic device, comprising:

• a microfluidic channel;
• a series of reaction cells arranged in the microfluidic channel;
• each reaction cell of the series configured as an electrochemical transducer translating an applied voltage or current into a change of pH within the reaction cell, each reaction cell having arranged therein an FET sensor, which comprises a sensing surface, the sensing surface being functionalised with moieties suited for the sequential removal of an amino acid from a terminus of the peptide, the terminus being the N-terminus or the C-terminus of the peptide;
• a fluid management system for controlling transfer of liquids in the microfluidic channel;
• and
• a controller operatively connected to each reaction cell for controlling the pH therein, to the FET sensor of each reaction cell for measuring the surface potential of the FET sensor and to the fluid management mechanism.