Project Overview

I specialize in creating high-precision Standard Operating Procedures (SOPs) for chemical and biological engineering. This sample demonstrates my ability to document complex wet-lab protocols that require strict adherence to timing, temperature, and stoichiometry.

Context:
This protocol was developed to standardize the production of silk fibroin solutions for use in biodegradable neural interfaces. It transforms a variable raw material (cocoons) into a precisely quantified medical-grade solution.

Sample: Aqueous Silk Solution Preparation

1. Degumming (Sericin Removal)

• Preparation: Rapidly boil 3L of 0.02 M Na2CO3 solution. Note: Ensure the hot plate is set to maximum; heating 3L of water takes ~1 hour. Plan accordingly.
• Boiling: Add cut silk cocoon pieces only when water is rapidly boiling (large bubbles). Simmering water is insufficient for complete sericin removal.
• Duration: Boil for exactly 60 minutes, stirring intermittently.
• Rinsing: Transfer silk to boiling deionized (DI) water for 20 mins, then rinse three times in room-temperature DI water to remove salt residues.

2. Dissolution & Dialysis

• Solvent: Dissolve dried silk fibers in 9.3 M Lithium Bromide (LiBr) at 60°C for 1-3 hours.
  • Calculation: Vol(LiBr) = Mass(Silk) × (100 mL / 20 g).
• Dialysis: Inject solution into 3.5k MWCO dialysis tubing. Dialyze against 1L of DI water for 48 hours, changing the water at 1h, 4h, and 24h intervals to ensure complete salt removal.

3. Concentration Adjustment
After filtration, the final concentration is adjusted to 7-8% (w/v) using gravimetric analysis.

Adjustment Calculation:
To reduce concentration to target, use the dilution equation: Vi x Ci = Vf x Cf

• Example: If you have 6 mL of 11% solution and target 7%:
  • 6 mL x 11% = Vf x 7%
  • Vf = 9.43 mL
  • Action: Add 3.43 mL of DI water to reach the target volume.

Project Overview

As a Ph.D. scientist, I provide critical peer review and editorial services. This redacted sample demonstrates my ability to evaluate scientific rigor, methodology, and logic. I have extensive experience editing manuscripts for non-native English speakers, ensuring that complex scientific ideas are communicated with native-level fluency and clarity.

Document Type: Formal Peer Review Report
Recommendation: Major Revisions

Sample Critique

1. Electrochemical Impedance Spectroscopy (Page 8, Line 174)
The data shows the impedance magnitude increasing at frequencies higher than 10^5 Hz. This behavior is physically inconsistent with standard electrode models, where high-frequency impedance should represent the solution resistance (a constant value). This anomaly suggests a potential artifact in the measurement setup that must be addressed before publication.

2. Unsupported Mechanical Claims (Page 3, Line 64)
The authors highlight “reducing mechanical mismatch” as a primary justification for the design but fail to characterize the mechanical properties of the bulk needle material. Since the PEDOT layer likely contributes negligibly to the overall stiffness compared to the bulk polymer, the authors must provide the Young’s modulus of the needle itself to substantiate this claim.

3. Reference Electrode Validity (Methods, Line 305)
The protocol describes using a Ag/AgCl wire directly in acetonitrile without a salt bridge. This configuration is known to cause potential drift and contamination. Standard practice for non-aqueous solvents requires a double-junction reference electrode to ensuring reproducibility.

4. Charge Transfer Analysis
The manuscript claims “enhanced” charge transfer properties but does not normalize the current by the geometric surface area. Without reporting the current density, it is impossible to determine if the improvement is due to the material properties of the PEDOT coating or simply an increase in effective surface area from the vertical extension.

Project Overview

This preprint (10.1101/2025.09.29.679383) excerpt demonstrates my ability to synthesize complex interdisciplinary concepts (microfabrication + neuroscience) into a clear, compelling scientific narrative.

Publication Title: Beyond the Straight Path: High-Density Laminar Recordings in the Ventral Hippocampus with Curved Microprobes

Abstract

Brain function is governed by neural circuits distributed across an intricate, three-dimensional landscape of anatomically complex structures. Current methods for monitoring neural activity are limited to investigating structures that lie along a single, linear trajectory. While this approach is effective for columnar regions, such as dorsal cortical areas or the relatively planar dorsal hippocampus, it fails in deep or curved structures, like the ventral hippocampus, where a linear probe can only achieve with difficulty the combination of physical access and perpendicular orientation required for recordings across all layers.

To overcome this limitation, we developed a multisite microelectrode array with a pre-formed curved geometry, engineered to align perpendicularly with neuronal layers in deep anatomical targets regardless of their orientation. This interface integrates a polymer-based array, featuring 16 PEDOT:BF4-coated microelectrodes for robust signal acquisition, with a dissolvable silk stiffener for precise surgical insertion. The resulting device exhibited excellent electrical properties (avg. impedance 18 kΩ) and enabled accurate placement across the distinct neuronal layers of the ventral hippocampus CA1 region. These capabilities allowed for successful recordings of both local field potentials and single-unit activity from this region, providing a powerful new tool to investigate the network dynamics of previously inaccessible neural circuits.

Introduction (Excerpt)

A fundamental mismatch exists between the intricate, three-dimensional architecture of the brain and the linear design of the tools used to study it. For nearly a century, deep brain-penetrating electrodes have relied on a single, straight geometry, creating a critical blind spot in our ability to investigate non-planar neural circuits. This limitation is especially pronounced when accessing deep or curved regions, such as the ventral hippocampus, where a straight probe cannot simultaneously achieve physical access and maintain a perpendicular orientation to the target’s neuronal layers. This gap in our technological capabilities prevents high-fidelity recordings from many circuits essential for understanding complex behaviors and neurological disorders.