Graphene oxide (GO) is a carbon material with wide chemistry, and its functionalization represents the main challenge to develop multi-functional materials for different applications. Besides to epoxide and carboxyl groups, the alkenes that arise during the graphite oxidation seem to provide an excellent approach for developing selective reactions. In specific, α,β-unsaturated acids can be functionalized by thiol-ene Michael addition (TEMA) using base catalysts. However, when base catalysts are used, the thiol-epoxide ring opening reaction (TEROR) has been considered as the predominant and unique reaction. Therefore, there is a need to understand the reactivity of the GO when TEMA and TEROR take place from a qualitative and quantitative point of view. Herein, we studied the functionalization of GO and reduced graphene oxide (RGO) with cysteamine (CA) using different base catalysts. XPS results revealed that despite the thermal reduction of GO, the functionalization was possible confirming the coupling reaction between the CA and α,β-unsaturated acids of RGO by TEMA. In addition, a quantitative analysis was conducted via fluorescent labelling corroborating that TEMA produced more CA molecules bonded to GO than TEROR.

氧化石墨烯（GO）是一种化学性质广泛的碳材料，其功能化是开发用于不同应用的多功能材料的主要挑战。除了环氧基和羧基外，在石墨氧化过程中产生的烯烃似乎为开展选择性反应提供了极好的方法。具体而言，α，β-不饱和酸可以通过使用碱催化剂的硫醇-烯基迈克尔加成（TEMA）来官能化。然而，当使用碱催化剂时，硫醇-环氧开环反应（TEROR）被认为是主要且独特的反应。因此，有必要从定性和定量的角度了解当TEMA和TEROR发生时GO的反应性。在这里 我们研究了使用不同的碱催化剂对GO和半胱胺（CA）还原氧化石墨烯（RGO）的功能。XPS结果表明，尽管GO发生了热还原，但官能化仍可能通过TEMA证实CA与RGO的α，β-不饱和酸之间的偶联反应。另外，进行了定量分析通过荧光标记证实了TEMA产生的与GO结合的CA分子比TEROR多。