中文摘要：

石墨烯是一种具有单原子厚度的二维碳纳米材料，具有大的比表面积、高的导电性和室温电子迁移率，以及优异的机械力学性能. 石墨烯还具有电化学窗口宽，电化学稳定性好，电荷传递电阻小，电催化活性高和电子转移速率快等电化学特性. 化学修饰石墨烯，特别是氧化石墨烯（GO）和还原氧化石墨烯（rGO），可以被宏量、廉价地制备出来. 它们具有可加工性能，可以被组装、加工或复合成具有可控组成和微结构的宏观电极材料. 因此，石墨烯及其化学修饰衍生物是用于电化学生物传感的独特而诱人的电极材料. 例如，GO是一种化学修饰石墨烯，也是石墨烯的重要前驱体；其边缘具有大量的羧基可用于共价固定酶，从而能实现酶电极的生物检测. 在GO上的不可逆蛋白吸附也可以促进蛋白质的直接电子转移以提高其电化学检测性能. 但是，GO大量的含氧官能团破坏了石墨烯本征的共轭结构，降低了其电学性能并限制了其实际应用. GO可以通过化学、电化学、热还原等技术转化成rGO，从而能部分修复其共轭结构，提高其导电性与传感性能. 另一方面，石墨烯是一种零带隙材料；原子掺杂可以调控其能带结构，提高其电催化性能. 石墨烯材料也常常需要通过与其它功能材料的复合进一步改善其可分散与可加工性能，提高其电催化活性和电化学选择性. 本文综述了本征石墨烯（包括GO，rGO和掺杂石墨烯）以及石墨烯与生物分子、高分子、离子液体、金属或金属氧化物纳米粒子等复合材料修饰电极在检测各种生物分子方面的研究进展，并对该研究领域进行了展望.

英文摘要：

Graphene has a unique atom-thick two-dimensional structure and excellent properties, including high conductivity and electron mobility at room temperature, large specific surface area, and excellent mechanical properties. Graphene also possesses a variety of promising electrochemical properties, such as a wide potential window, low charge-transfer resistance, high electrocatalytic activity and fast electron transfer rate. Furthermore, chemically modified graphene materials, particularly graphene oxide （GO） and reduced graphene oxide （rGO）, can be produced in a large scale and at low costs. They have good processability and can be assembled, blended or fabricated into macroscopic electrode materials with controlled compositions and microstructures. Thus, graphene and its chemically modified derivatives are unique and attractive electrode materials for electrochemical biosensing. For example, GO is a chemically modified graphene and an important precursor of graphene. GO sheets have a large amount of carboxyl groups at their edges, which can be used to covalently immobilize enzymes, realizing the detection of biomolecules. GO can also enhance the direct charge transfer of protein because of its irreversible adsorption to protein and abundant catalytic sites. However, the oxygen functional groups of GO heavily destroy the conjugated planes of graphene sheets, decreasing the electrical property and limiting the practical applications of GO. Chemical, electrochemical, or thermal reduction can partly restore the conjugated structure, converting GO to conductive rGO. On the other hand, graphene is a material with zero band gap. Doping graphene with heteroatoms can modulate its band gap and improve its electrocatalytic properties. Graphene materials also frequently have to be blended with other functional materials to improve their dispersibility and processibility, enhance their electrochemical activity and/or selectivity. This review will summarize the recent research achievements in electrochemical biosensing