Abstract: Biosensors capable of detecting certain biomarkers (e.g., platelet-derived growth factor-BB (PDGF-BB)), as well as methods of fabricating the same and methods of using the same, are provided. The biosensors can be disposable and/or label-free. Electrochemical bipolar exfoliation can be used to exfoliate, reduce, and deposit (in a single step) graphene nanosheets on a desired substrate (e.g., an electrode). Affinity aptamers can be immobilized on the graphene nanosheets disposed on the substrate.

Abstract: Biosensors capable of detecting certain biomarkers (e.g., platelet-derived growth factor-BB (PDGF-BB)), as well as methods of fabricating the same and methods of using the same, are provided. The biosensors can be disposable and/or label-free. Electrochemical bipolar exfoliation can be used to exfoliate, reduce, and deposit (in a single step) graphene nanosheets on a desired substrate (e.g., an electrode). Affinity aptamers can be immobilized on the graphene nanosheets disposed on the substrate.

Abstract: Microsupercapacitors (MSCs), as well as methods of fabricating the same and methods of using the same, are provided. An MSC can include interdigitated microelectrodes having reduced graphene oxide (rGO) (e.g., vertically aligned nanosheets thereof) disposed on upper surfaces of the microelectrodes. The MSC can be fabricated by preparing a micro-current collector (MCC) comprising the interdigitated microelectrodes using photolithography and then performing a bipolar electrochemistry process on the MCC to deposit rGO on the upper surfaces of the interdigitated microelectrodes (e.g., in a single-step in situ exfoliation, reduction, and deposition).

Abstract: Bipolar electrochemistry (BPE) concepts are used to provide a single-step and controllable process for simultaneously exfoliating a graphite source and depositing both graphene oxide and reduced graphene oxide layers on conductive substrates. A bipolar electrochemical cell can be used for a three-in-one deposition and can include two wired pieces of graphite to monitor the amount of current that passes through the bipolar electrode.

Abstract: Bipolar electrochemistry (BPE) concepts are used to provide a single-step and controllable process for simultaneously exfoliating a graphite source and depositing both graphene oxide and reduced graphene oxide layers on conductive substrates. A bipolar electrochemical cell can be used for a three-in-one deposition and can include two wired pieces of graphite to monitor the amount of current that passes through the bipolar electrode.

Abstract: Single-step, inexpensive, scalable, and eco-friendly methods and systems for exfoliation and deposition of 2D reduced phosphorene nanosheets are provided, as well as deposited phosphorene nanosheets with high specific capacitance. The exfoliation and deposition can be in situ and can include exfoliation from bulk black phosphorus (BP) into a solvent and deposition onto a negative feeding electrode. The positive feeding electrode can be a noble metal, such as a platinum wire.

Abstract: A single-step, in situ bipolar exfoliation system, and methods for exfoliations of multi-layer bulk black phosphorous into single-layer (two-dimensional), few-layer, or even nano-platelets phosphorene are provided. The bipolar exfoliation system can include: a first driving electrode; a second driving electrode electrically connected to the first driving electrode through an external power supply; at least one bipolar electrode comprising multi-layer bulk black phosphorous; and a solvent in physical contact with the first driving electrode, the second driving electrode, and the at least one bipolar electrode. The system can be configured such that the electric conditions between the first and second driving electrodes can be used to turn one end of the at least one bipolar electrode into an anodic pole and the other end of the at least one bipolar electrode into a cathodic pole such that the multi-layer black phosphorous is exfoliated into the single-layer, few-layer, or nano-platelets phosphorene.